Patent Abstract:
A joining strip is provided by which sheet metal may be formed into a hollow tubular panel. The joining strip provides a seam between panel edges that acts as a thermal break between inner and outer faces of the panel. The joining strip may also carry a resilient tubular cushion which extends into the joint between the side ends of two panels that are connected by a hinge. This cushion contributes to providing an air seal within the joint between the two panels. Applications include roll-up garage doors and roll-away, articulated walls.

Full Description:
FIELD OF THE INVENTION 
     This invention relates to sheet metal panels that are provided with a thermal break. It also relates to doors made from a series of such panels joined by hinged couplings to serve in a garage door or the like. In particular the invention relates to a method of sealing such joints to minimize the passage of air there through. 
     BACKGROUND TO THE INVENTION 
     Various technologies have been applied in the past to the joining of sheet metal panels to form doors having inner and outer faces. Further, such panels have been assembled with a series of hinged joints to provide a roll-up door. A particular application of this technology has been in the fabrication of garage doors. 
     It is useful to provide a thermal break between the pieces of sheet metal forming the inner and outer surfaces of a barrier such as a door. Particularly when the sheet metal is aluminum or steel, thermal conduction from an outer panel exposed to low temperatures can lead to the cooling of the inner panel with resulting condensation. Such condensation can eventually cause corrosion and damage to the door and its parts. 
     It is therefore one object of this invention to provide a means for joining two panels together that provides a thermal break for such panels. 
     It has been known to provide special shapes for adjoining edges of panels which are hinged to each other in order to minimize the risk that an object, e.g. a finger, may be pinched in the joint when the joint closes. Such edges are often provided with shapes of complementary curvature that permit the panels to be either aligned into a planar format, or oriented at an angle with respect to each other. Typically, one edge is generally of a convex, somewhat parabolic shape, while the other edge is concave with a complementary curvature. This minimizes the amount of gap that is formed when the joint opens. 
     The present invention incorporates into such a joint a sealing feature which minimizes the loss of air which might otherwise flow through the joint. 
     The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification. 
     SUMMARY OF THE INVENTION 
     In one broad aspect, the invention is a flexible joining strip preferably of resilient polymeric material providing two parallel slots to receive edges from respective inner and outer portions of a modular panel that is to form part of a roll-up door or wall. These panel portions are of a sheet material, preferably sheet metal. A central web separating the two slots provides the joining strip with a partially “M”-shaped cross-section. The central web extends below the base of the “M” to terminate in an inverted “T”-shaped flange with outwardly-extending lateral portions. The respective lateral portions of the “T” extend across the direct, aligned path of entry into the respective slots. The flange on the central web is, however, displaced sufficiently below the base of the “M” to provide an access path for entry of sheet edges into the respective slots. 
     The material of the joining strip has a thermal conductivity which is less than that of a metal. Thus, when serving to bind the seam between two metal sheets, the joining strip will provide a thermal break. The sealing strips may be fitted to the edges of the panel portions by sliding such strips onto the edges endwise. Alternatively, by forming the joining strip from material of a flexible nature, particularly when warmed, the outer sides of the slot may be flexed to admit the entry of the edges of the sheet material into the respective slots. Those edges may be bent or of a “hooked” shape in cross-section to fit into the slots. The flange is positioned to block the direct removal of the preferably hooked edges from the slots. This provides a stable coupling between the two edges of the sheet material panel portions. 
     When a panel is to be formed by joining two separate metal panel portions together, the paired edges along the top and bottom of both of the inner and outer sheet metal panel portions may be joined along their longitudinal edges to provide an inner, enclosed volume. Alternately, a single sheet of metal can be bent to provide both the inner and the outer faces of the panel. In this latter case only a single pair of edges need be joined by the joining strip to provide a single seam. While this arrangement is an option, a disadvantage of this arrangement is that the sheet metal along one edge of the panel is continuous, without a thermal break being present. For maximum thermal isolation, panels should be formed with separate inner and outer sheet metal portions, joined by two, upper and lower seams. Further and preferably, such two piece panel portions are symmetrical when assembled, allowing such parts to be produced from a single production die. Also preferably, the interior volume of each panel is filled with a stiffening insulation material such as polyurethane foam. 
     As a preferred feature, the outer face of the flange portion of the web on the joining strip carries a sealing member in the form of a hollow, flexible tubular cylinder which can be compressed into a flattened position adjacent to the flange to provide a sealing member. Preferably this tubular cylinder is made of a resilient material. When panels are assembled into an articulated door or wall, at least one seam should be equipped to provide a sealing member along a joining strip. Preferably two seams from adjacent panel longitudinal sides or ends may be provided with sealing members that contact each other and provide an improved airtight seal for a door when closed. By use of compliant material for the sealing member, the sealing member may be compressed within the space between adjoining seams of two door panels when the panels are brought into planar adjustment. It is not, however, necessary, for both joining strips to carry sealing members. It is sufficient for one joining strip to provide the necessary seal. 
     To allow panels to be assembled into an articulated wall or door having pinch-resisting joints, one of the longitudinal boundary edges or faces of each panel is preferably shaped to be generally convex, while the other longitudinal edge face is generally concave. The precise shape of these ends is selected to provide a close but not obstructing fit between these respective faces when one panel is rotated about a hinged axis with respect to the other panel. In the course of this rotation a portion of the joining strip, or sealing member if present, positioned along the seam formed on either the concave or the convex end of one panel may brush against the inner surface of the end of the other panel. This contact provides a barrier to entry of objects into the joint. Contact as described is permissible, however, only to the extent that motion between the two parts is not obstructed. 
     In this manner a joint is provided which provides a minimal gap that may pinch a person&#39;s fingers, acts as a thermal break between the inner and outer sheet metal portions of each panel, and further serves to create an airflow-resisting seal along the joints between panels when the panels are flattened out into a planar orientation with respect to each other. 
     The foregoing has provided a description of the invention and some of its optional aspects. The invention may be further understood by the description of the preferred embodiments, in conjunction with the drawings, which now follow. 
    
    
     SUMMARY OF THE FIGURES 
     FIG. 1 is a schematic perspective view of a cross-sectioned sealing strip of the invention with the edge of a sheet metal panel positioned adjacent thereto, prior to being inserted into the sealing strip. 
     FIG. 2 is an end view of a garage door in perspective showing sheet metal hinged panels joined by sealing strips as in FIG.  1 . 
     FIG. 2A is an enlarged end view detail of the joint between two sheet metal panels as in FIG.  2 . 
     FIG. 2B is an enlarged end view detail of the bottom edge of the bottom panel of the door of FIG.  2 . 
     FIG. 3 is a progressive series of detailed end views of the closing action of the joint between adjacent panel edges of the door of FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIG. 1 a sealing strip  1  has a central web  2  and two outer strips  3  that, along with web  2 , provide an “M”-shaped cross-section. 
     The web  2  extends below the “M” to terminate in a flange  4 , being of an inverted “T” shape in cross-section. The flange  4  has two laterally extending flange portions  5   a ,  5   b.    
     The flange portions  5   a    5   b  extend across the path  6  for direct entry into slots  7  present within the “M”. The flange portions  5   a ,  5   b  are also displaced from the base of the “M” to provide an access path  8  for metal edges  9  on a sheet metal panel portion  10  to extend outwards from the slots  7 . 
     The sheet metal panel portion  10  is part of a sheet metal panel  11  shown in FIG. 2 composed of two panel portions  10  and having inner  12   a  and outer  12   b  faces and upper  13   a  and lower  13   b  longitudinal panel edge face. Conveniently, these panel portions  10  are symmetrical when assembled, allowing a single style of part to be used for either face  12   a ,  2   b  of a panel  11 . As shown in FIG. 2 the upper panel end  13   a  is preferably convex and the lower end  13   b  is concave. 
     The shape of the respective panel ends  13   a ,  13   b  are such as to provide a non-obstructing rotation of one panel  11  with respect to an adjacent panel  11   a  about a laterally mounted hinge  14 . This is shown in detail in FIG.  3 . Preferably the longitudinal edge face of each panel are symmetrical about a central plane lying between the two face portions. This shape also minimizes the presence of a gap  23  wherein a person&#39;s fingers may become pinched. 
     The joining of the inner  12   a  and outer  12   b  panel faces is effected along seams  16   a ,  16   b  within the longitudinal edge faces  13   a ,  13   b . A sealing strip  1  present at each seam  16   a ,  16   b  receives edge portions  9  from each of the panel faces  12   a ,  12   b . This is shown in detail in FIG. 2A, wherein the “M” of the joining strip is positioned towards the interior of the panel, and the inverted “T” of the joining strip is positioned towards the exterior of the panel. 
     In FIG. 2 both the top  13   a  and bottom  13   b  panel longitudinal edge faces, or “longitudinal faces”, have seams  16   a ,  16   b . One sheet of metal could, however, be bent to form a panel  11  with a single seam. The interior volume of each panel  11  is preferably filled with an insulating and structural stiffening material such as polyurethane foam  25 . This is shown pictorially in the top panel  11   c  of FIG. 2 by the field of dots. 
     The panels  11  are modular to permit assembly into a roll-up door or the like. The panel longitudinal face  13   c  of the bottom panel  11  may receive a capping member  17  that fits over the face  13   c . The bottom of the capping member  17  is preferably fitted with a resilient semi-circular strip  18  to serve as a bumper or edge protector when the door approaches the floor. The capping member  17  may also optionally include a sealing strut  24  extending to the seam  16   b.    
     At the top of the door, a resilient strip  26  may seal the top boundary longitudinal face  13   d  of the door against a frame when the door is closed. 
     The sealing strip  21  fitted along the bottom face of the flange  4  on each sealing members  21  is dimensioned and positioned to create a seal with an adjacent panel longitudinal face  13   a ,  13   b  when the panels  11  are in a coplanar orientation i.e., when the door is closed. Such sealing members  21  may be present on one or both of the seams  16   a ,  16   b  of abutting panels  11 . As well as providing a seal, the sealing members  21  can act as a cushion and reduce noise arising from opening or closing of the door. 
     In FIGS. 2 and 2A two strips  1  on adjacent panels  11   a ,  11   b  virtually abut with each other when the panels  11   a ,  11   b  are in a planar orientation to each other. This deforms the sealing members  21  due to their intimate contact with each other, providing an air seal. While shown as a tubular, resilient, partial cylindrical member in FIG. 1, this sealing member  21  may also be in the form of resilient strips (not shown), e.g. the cylindrical member may be slit longitudinally. The object is simply that the sealing member  21  will serve as a seal. 
     The sealing effect with cylindrical sealing members  21  is shown progressively in FIG. 3 where the stages of closing a garage door are depicted. Panels  11   a ,  11   b  rotate about hinge  14  towards closing. The edge faces  13   a ,  13   b  are shaped to minimize the risk of pinching an object in the closing gap  23  between the edges  13   a ,  13   b . The sealing strip  1  with sealing member  21  on the convex face  13   a  just brushes against the surface of the concave face  13   b  as closing proceeds. When the sealing members  21  on the strips contact each other, they deform and flatten to provide the seal and cushioning effect. 
     The hinge  14  is preferably positioned on the panel face surface  12   b  of each panel  11 , at the point  24  where faces  13   a ,  13   b  meet. With the hinge  14  at this location  24 , surface points  25  on the moving panel longitudinal face  13   b  follow a circular trajectory about the hinge axis. The remote portion  26  of longitudinal face  13   a , removed from the hinge  14 , may also be curved in a similar circular path. In this manner, the gap  23  is minimized for a substantial portion of the closing action. 
     An inflection zone  27  in the end faces  13   a ,  13   b  near the outer face portions  12   a  of each panel portion  10 , located opposite to the hinge  14 , can be shaped to close the gap  23  when the door is closed. At this inflection zone  27 , the longitudinal faces  13   a ,  13   b  may come fully into contact presenting a closed surface on the face of the door opposite to the hinge. 
     CONCLUSION 
     The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, and more specific aspects, is further described and defined in the claims which now follow. 
     These claims, and the language used therein, are to be understood in terms of the variants of the invention which have been described. They are not to be restricted to such variants, but are to be read as covering the full scope of the invention as is implicit within the invention and the disclosure.

Technology Classification (CPC): 4