Patent Publication Number: US-7900682-B2

Title: Garage sectional door insulation system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
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     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to an insulation system for garage sectional doors. More particularly, the invention relates to an insulation system that provides thermal and audio insulation to a door comprised of multiple sections, such as a garage door. 
     2. Prior Art 
     It is convenient for large doors, such as a garage door, to be designed as a series of horizontal sections. The sections are typically divided into panels by a series of stiles and connected to one another by hinges. A series of wheels engage a pair of rails extending along an opening and ceiling of a garage. The garage door is opened by raising the sectional door along the rails until it is engaged with the ceiling portion of the rails. It is preferable to facilitate the opening process by using lightweight material to construct the door. 
     Garage door sections are typically made of a single, thin wall of sheet metal. This allows the door sections to be light weight and extremely durable. However, sheet metal is very thermally conductive and provides very poor insulation. Garages are consequently a major source of leakage of a controlled climate. This significantly adds to the cost of heating or cooling a structure having a garage. It also makes them impractical for use as an indoor activity area in addition to a storage facility. 
     It is known to construct garage doors having insulation between two metal walls, as shown in U.S. Pat. No. 5,435,108 to Overholt et al. Such a design adds significant cost to the manufacturing of the door and is not suitable for retrofitting existing doors. 
     U.S. Pat. No. 5,787,677 shows a garage door insulation system that has an outer wall of sheet metal, an inner wall of concrete and an insulating layer. Concrete adds considerable weight. And the multi-layer process significantly complicates manufacture of the door. This design is also not conducive to retrofitting insulation to existing garage doors. 
     More recently, various retro-fit insulating kits have become available for garage doors. These kits allow an insulating material to be applied to existing sectional doors. Typically, they require an insulating material to be permanently attached to the inside of a sectional door panel by means of an adhesive. 
     Adhesives that effectively bond to a metal surface typically are corrosive to many materials, are toxic and many such glues emit unpleasant and/or toxic fumes. This is disadvantageous because the insulation is applied while the garage door is in the closed position. This necessarily requires that a person applying a glue be exposed to the toxic fumes in a closed room without ventilation. Furthermore, metal substantially expands and contracts as temperature changes. This causes the bonding between a metal sectional door and its insulation to deteriorate. An adhesive itself is often susceptible to degradation when exposed to extreme conditions. Insulation must therefore be periodically reattached or replaced. 
     Many garage door insulation kits also require the use of tools and application of substantial force to the components. The difficulty and complexity of installing these kits make them impractical and unappealing to persons with limited home improvement skills and ability. 
     Metal garage and other sectional doors typically have upper and lower walls and protruding lips that provide strength. They often include vertical stiles also having strengthening lips. Insulating sheets having the proper dimensions can be inserted into the void space of the panels of these door sections to provide insulation. However, the insulating sheets are not locked in securely and may loosen and move about. This increases wear on the insulating sheets. It also creates a potential hazard as a sheet may detach and fall, especially when the door is in the up position. It is also not aesthetically pleasing. 
     It is therefore desirable to provide a means for retrofitting insulation to existing sectional doors. 
     It is also desirable to provide a means for easily retrofitting insulation to existing sectional doors that does not require adhesives or tools and substantially fills void spaces in the doors. 
     It is also desirable to provide a means for easily retrofitting insulation to existing sectional doors that has an aesthetically pleasing appearance. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system for insulating sectional doors including pre-existing garage doors. Installation requires no tools, tape or adhesives. It preferably has a textured outer surface that is aesthetically pleasing. The insulation panels of the invention are light weight and covered by a protective sheet to prevent damage. 
     The invention is comprised of an insulating block of material that is bonded directly to a polymer sheet. The insulating block is preferably exposed to the polymer sheet during the curing process such that the material of the block contacting the sheet is integrated into the matrix of the polymer as it cures in order to tightly bond the insulating block to the protective sheet without the need for glue or other adhesive. This method of bonding the block and the sheet together is generally preferred to most methods using an adhesive. 
     The insulating block has two grooves formed on its upper and lower surfaces between the insulating block and the protective sheet. The block has sloped top and bottom surfaces and an outer surface that is sized to fit into a void space on the interior wall of a sectional door. The block is formed of an insulating and mildly compressible material, such as expanded polystyrene (EPS). Because the block is compressible, the invention may be pressed in to the void space of a door. Brackets extending from the upper and lower walls of the door section are accommodated within the grooves and hold the insulating block firmly in place. If a door section is partitioned into individual panels by a series of vertical stiles, the insulation panel may be comprised of one protective sheet wide enough to cover an entire door section and having a plurality of insulation blocks designed to fit into the individual cells between the stiles. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. 
     Optionally, a thin foil barrier is included on the surface of the insulating block within the void, which may or may not be in contact with the outer wall of the door section. Insulating inserts may also be optionally inserted in the void space of the door section behind brackets and stiles to further insulate the door. 
     It is therefore an object of the invention to provide a sectional door insulation system that is lightweight and easy to install. 
     It is another object of the invention to provide a sectional door insulation system that is lightweight and easy to install and has a protective outer covering that may be formed or modified so that it is aesthetically pleasing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an insulation panel of the invention. 
         FIG. 2  is a side view of an insulation panel engaged with a door section. 
         FIG. 3  is a stepwise diagram of a method of manufacturing an insulation panel of the invention. 
         FIG. 4  is a perspective view of an alternative embodiment of the invention. 
         FIG. 5  is a perspective view of the embodiment of  FIG. 4  engaged with a door section. 
         FIG. 6  is an enlarged side view of a groove of the invention. 
         FIG. 7  is an enlarged side view of an alternative embodiment of a groove of the invention. 
         FIG. 8  is an enlarged side view of an alternative embodiment of a groove of the invention. 
         FIG. 9  is an enlarged side view of an alternative embodiment of a groove of the invention. 
         FIG. 10  is an alternative embodiment of the invention. 
         FIG. 11  is a perspective view of a tab of the alternative embodiment of the invention of  FIG. 10 . 
         FIG. 12  is an alternative embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention provides an apparatus and method for easily providing substantial insulation for a sectional door, such as a garage door. The invention may be used for any suitable door or structure having one or more void spaces. The invention is especially suited for sectional doors having brackets or other protrusions around a void space that may engage a groove in the insulating panel. The insulating panels of the invention are light weight and are installed by simply pushing the insulating block into a void space. The invention is therefore well suited for garage doors that are already installed and in use. The invention may also be incorporated into a sectional door at the time of manufacture or prior to installation. The invention may be installed by professional installers or persons having little or no skill in the art of insulation installation. Anyone may use the invention to readily, safely and effectively insulate storage areas in an aesthetically pleasing manner. 
       FIG. 1  shows a perspective view of a basic insulation panel  10  of the invention. The panel  10  is comprised primarily of insulating block  12  and protective sheet  14 . Block  12  has an outer surface  20  with a height  7 , a sloped top surface  21 , a sloped bottom surface  23  and two sides  22 . The insulating block  12  is bonded to protective sheet  14  at interface  16 . Protective sheet  14  has a top  25 , a bottom  27 , and end  26 . 
     Top groove  15  is located between top surface  21  and protective sheet  14 . Top lip  11 , top shelf  17  and top groove floor  13 , form a top indentation in block  12 . Protective sheet  14  joins block  12  at interface  16 , thereby combining with the top indentation of block  12  formed by top lip  11 , top shelf  17  and top groove floor  13  to form top groove  15 . Similarly, groove  18  is located between bottom lip  23  and sheet  14 , formed by sheet  14  and the indentation formed by bottom lip  31 , bottom shelf  19  and bottom groove floor  29 , which similarly ends at interface  16  with sheet  14 . Groove floors  13  and  29  define the deepest recess points of grooves  15  and  18 , respectively. Grooves  15  and  18  lie between block  12  and sheet  14  and facilitate secure attachment of the insulation panel  10  to a garage door section or other structure. Grooves  15  and  18  are designed to accommodate opposing top and bottom brackets or other structures that are spaced apart a distance less than the distance between upper lip  11  and lower lip  31  but greater than or equal to the distance between floors  13  and  29 . Lips  11  and  31  are sufficiently compressible to allow brackets or other structures to be slid along top surface  21  and bottom surface  23 , thereby compressing lips  11  and  31  until the brackets or other structures enter grooves  15  and  18 . Lips  11  and  31  are sufficiently rigid such that they decompress once the brackets or other structures enter grooves  15  and  18  and such that they adequately retain the brackets or other structures firmly within grooves  15  and  18 . 
     It is preferred to use a very lightweight insulation material to form the block  12  of the invention. Insulating block  12  is preferably formed from thermally insulating material that is lightweight and slightly compressible, at least along the top surface  21  and bottom surface  23 . Expanded polymers, such as, but not limited to, expanded polystyrene (EPS), expanded polyurethane, expanded polyolefins, foam rubber, combinations thereof and like materials having these qualities are optimal for use with the invention. Those skilled in the art will appreciate that such expanded, porous polymers are inexpensive, readily available, easy to form and insulating. For these and other reasons, such materials are well suited for the invention. However, other materials that are both insulating and slightly compressible are similarly well suited for the invention. 
     As explained herein, block  12  is preferably compressible along its top surface  21  and bottom surface  23 . Block  12  may therefore be comprised of more than one material. Optionally, block  12  may be comprised of one or more core blocks of a less compressible material and surrounded by a more compressible material, thereby providing compressibility along top surface  21  and bottom surface  23 . Optionally, block  12  may include one or more cavities that may or may not be fillable with one or more materials. For example, block  12  may be comprised of a slightly compressible but still somewhat firm material such as an elastomeric material such as rubber or the like, and having a cavity at least partially filled with an insulating very lightweight and very compressible material, such as but not limited to foam rubber. Construction of block  12  may be further complicated by using noncompressible insulating materials having a top and bottom surfaces and lips that are compressed by means of a spring mechanism. Such spring loaded tabs are well known in the art and are commonly used as tabs for locking or snapping objects into place. However, it is generally preferred for simplicity of manufacture that block  12  be formed having non-moving parts and more preferably being comprised of a single, solid material. 
     Top surface  21  is sloped downward from lip  11  to outer surface  20 . Bottom surface  23  is sloped upward from lip  31  to outer surface  20 . Sides  22  are therefore substantially trapezoidal in shape, and the entire block  12  has a substantially trapezoidal vertical cross section. Preferably, height  7  of outer surface  20  is less than the distance between top lip  11  and bottom lip  31 . The size of the outer surface  20  and angled slopes of top surface  21  and bottom surface  23  allow block  12  to be easily inserted into the void space of a sectional door or similar structure. 
     Sheet  14  is preferably about ½-⅛ inch thick. Thickness may vary so long as sheet  14  remains thick enough to provide protection for panel  10  and thin enough that it does not add unnecessary weight to panel  10 . It is attached to block  12  at interface  16 , preferably by chemical means. Sheet  14  may be comprised of any durable material. Polymer materials are inexpensive moldable, pliable and readily available and therefore well suited for use as a material to comprise a durable sheet for the invention. Polyureas are well suited for the invention. Polyurea is defined as a reaction product of an isocyanate prepolymer and an amine-terminated prepolymer resulting in a polymer based on a urea linkage group. Polyurea is preferred in the invention because of its extreme durability, strong resistance to corrosion, pliability and relatively mild curing process. The polyurea curing process makes it especially well suited for chemical bonding at interface  16  as described herein. However, other polymers that are similarly durable such as but not limited to polyurea/polyurethane blends, polyolefins and the like may also be used. Such other materials are preferably bonded by similar means as that described in  FIG. 3  and the accompanying text. However, adhesives, mechanical means such as screws, nut and bolts and the like, and other methods may be used to fixedly attach sheet  14  to block  12 . Interface  16  is preferably planar, as shown herein. However, interface  16  may comprise any of a variety of geometries so long as the bonding between block  12  and sheet  14  is sufficiently durable. 
       FIG. 2  shows the panel  10  of  FIG. 1  engaged to a garage door section  50 . Door section  50  is a typical horizontal section of a sectioned garage door. It has an outside wall  52  that faces the outside and the elements. Top wall  56  is designed to abut and engage a horizontal door section (not shown) above section  50 . Similarly, bottom wall  54  is designed to abut a door section below section  50  or the ground. Top wall  56  and bottom wall  54  are substantially perpendicular to outer wall  52  and extend inward. Upper bracket  58  protrudes downward from top wall  56  and lower bracket  59  protrudes upward from bottom wall  54 . Brackets  59  and  58  are generally substantially perpendicular to walls  54  and  56  respectively and are typically included in the manufacture of a garage door section to increase the strength and rigidity of the structure. 
     An insulating panel  10  is attached to garage door section  50  by a tongue and groove type interaction between grooves  15  and  18  and brackets  58  and  59  respectively. Because brackets  58  and  59  are rigid and grooves  15  and  18  are substantially rigid and designed to accommodate brackets  58  and  59 , panel  10  is held securely in place. Panel  10  is attached to a door section  50  in this way by simply pressing the panel  10  into the void space  51  of door section  50 . The height  7  of outer surface  20  of block  12  is preferably at least slightly smaller than the distance between brackets  58  and  59 . The top and bottom surfaces  21  and  23  of block  12  are slightly compressible, at least at the top lip  11  and the bottom lip  31 . This allows block  12  to be easily squeezed between brackets  58  and  59  without breaking or tearing. Panel  10  is pressed into void space  51  until the brackets  58  and  59  of the door section  50  insert into and thereby engage grooves  15  and  18 . Although lips  11  and  31  are compressible, grooves  15  and  18  are also sufficiently rigid so as to hold insulating panel  10  firmly engaged with door section  50 . 
     In  FIG. 2 , insulating block  12  does not fill the void space to the point that it is in contact with outer wall  52 . It is generally preferred for block  12  to occupy as much of void space  51  as practical. However, it is not necessary that it be attached to the inside of outer wall  52 . This feature of the invention provides one of the advantages over the prior art. Many prior art insulating panels must be attached to the inside of a door section by means of tape or adhesive. This makes installment of the insulating panels difficult. The present invention does not require adhesion to the inside walls within the void space. The combined features of the invention provide an easy to install, removable, durable and aesthetically pleasing insulation panel installable by a process that does not require any tools or adhesives. 
     Void space  51  varies according to the style and model of sectional door. In some instances, void space  51  will be larger than insulating block  12 . In addition, insulating block  12  does not substantially extend into the portion of the void space between the brackets and the outer wall. It may therefore be desirable to include inserts of insulating material in void space  51 , such as upper insert  55  and lower insert  53 . Such optional inserts provide additional insulation. Upper insert has a contact surface  67  that is flush with and engages top surface  21 . Lower insert  53  has a contact surface  61  that abuts and engages bottom surface  23  of block  12 . Bottom surface  23  includes a node  69  and a pocket  73  that engage complimentary node  77  and pocket  71  in contact surface  61  of insert  53 . These complimentary nodes and pockets allow the insert  53  and the insulating panel  10  to hold one another firmly in place. The nodes and pockets shown in  FIG. 2  are complimentarily concave and convex. However, engagement means of contact surface  61  and bottom surface  23  comprising nodes and pockets illustrate only one possible engagement means. Other geometries of engagement nodes and pockets are also suitable. Such engagement means are optional and may be included in one or both of top and bottom inserts. Alternatively, no engagement means may be used, as shown with top surface  21  and contact surface  67 . 
       FIG. 3  shows a process by which an insulating panel may be formed. In the first step  40 , a prepolymer  46  is sprayed by one or more nozzles  32  into a bed  30 . Sufficient prepolymer is added such that the sheet will form with the desired thickness. Bed  30  preferably has a textured design molded into it such that it may impart an aesthetically pleasing surface to the sheet once formed. As discussed above, polyurea polymers are well suited for the present invention. One of the reasons polyureas are preferred is their simple curing process which allows a protective sheet to be formed by simply spraying the prepolymers  46  into a molding bed  30 . 
     In the second step  42 , an insulating block  48  is placed in contact with prepolymers  46  as it cures. As prepolymers  46  polymerize, they interact with block  48  at interface  45 . The polymerization reaction engages insulating block  48 , and the block  48  becomes bonded to sheet  47  as the polymer cures. This step of the manufacturing process obviates the preference for a polymer having a mild curing process. Polyurea cures under ambient conditions that will not alter or modify EPS or other materials used to form the insulation block. Polyurea/polyurethane blends and other polymers suitable for the invention typically have mild curing conditions. Because the block  48  and sheet  47  become bonded during the curing process, there is no need for use of adhesives, other chemical bonding methods or mechanical bonding methods to hold the insulating panel together. However, accelerants, adhesives, curing agents and other compounds may be added to the interface  45 . 
     Once the prepolymers have cured, complete insulating panel  49  is removed from bed  30  in the final step  44 . The finished panel  49  has insulating block  48  firmly bonded to sheet  47  and is now ready to be used to insulate a sectional door. Sheet  47  has outer surface  24  that has a textured design molded into it by bed  30 . This design on surface  24  serves to make the insulating block more aesthetically pleasing than other insulation methods known in the art. It may mimic wood grain, or have any design desired, including artistic representations, logos symbols or the like. Coloring chemicals may be added to prepolymers  46 , or sheet  47  may be painted or otherwise treated to modify its color. When panel  49  is used to insulate a garage door, this aesthetically pleasing surface of sheet  47  gives the garage a look and feel of a real room as opposed to merely a storage area. Many people today use a garage for a variety of recreational activities, and such a design on surface  24  enhances this type of use of a garage space. 
     The process shown in  FIG. 3  is one preferred method of manufacturing the invention. However, more common methods may be used. The insulating block and protective sheet may be formed independently and attached by means any means known in the art to fixedly attach the materials the two components are made of. The interface between the two components may be formed by any fixed attachment means such as but not limited to adhesive chemicals, bonding chemicals, mechanical attachment methods or other methods known in the art. 
     Preferably, panels  49  are formed in a variety of sizes and shapes to accommodate sectional doors of varying sizes. Panels having the same dimensions may be grouped together as kits for insulating garage and other sectional doors that are already installed and in use. Such kits are easily used by a door owner to retro-fit an existing door according to the installation method described above. 
       FIG. 4  shows an alternative embodiment of the invention. Insulation panel  60  has two insulating blocks  62  attached to a single protective sheet. This embodiment may be used on a door section that has a vertical stile for structural support. Panel  60  is designed to engage a sectional door such that a vertical stile is accommodated between the two blocks  62 . Insulation panel  60  also includes barrier foils  66  on each block  62 . Barrier foils  66  are optional and comprised of a second insulating material. In this embodiment, the layers are comprised of two aluminum sheets with a polyethylene reinforcing mesh between them. It is not practical to place barrier foils between the sheet  64  and blocks  62  as this would not allow the bonding between them during the polymer curing process as shown in  FIG. 3 . However, it may be desirable to apply one or more barrier foils to the insulating block as shown in  FIG. 4 . 
       FIG. 5  shows panel  60  engaged with and secured to a garage door section  74 . Garage door  70  has door sections  72 ,  74  and  76  that are attached to one another by hinges  80 . Each section has a vertical stile  75  incorporated into it to provide support. Panel  60  is secured to section  74  by pressing insulating blocks  66  into the door section such that grooves  68  engage lips  82 . Surface  65  of panel  60  has a textured surface. Sheet  64  extends the length of door section  74 , covering and protecting insulating blocks  62  and stile  75  to provide a continuous panel. This gives the garage door a more uniform, attractive appearance. In this embodiment, two insulating blocks  62  are used to fit in a door section having one stile  75 . Door sections may have no stiles and be more suited for the embodiment shown in  FIG. 1 . Other doors may have sections having one stile as shown in  FIG. 5 . 
     It is known to have garage and other sectioned doors with a plurality of vertical stiles to strengthen the sections. Alternative embodiments of the invention may be manufactured to accommodate such designs by forming a series of insulating blocks on a single protective sheet such that the insulating blocks are spaced by gaps, similar to the one shown in  FIG. 5 , to engage the void spaces between stiles while the protective sheet creates a continuous interior surface along the length of a door section. It may also be desirable to include vertical insulating inserts behind the stiles similar to the upper and lower inserts shown in  FIG. 2 . 
     A continuous protective sheet is beneficial for aesthetic reasons, but also for protective reasons. A continuous sheet covering the void space of a door section minimizes the amount of moisture, debris and other objects, including insects that may enter the void space. This provides for a safer and healthier environment in the space enclosed by the sectional door. 
       FIGS. 6 ,  7 ,  8  and  9  show alternative embodiments of the groove of the invention.  FIG. 6  shows an enlarged view of the groove  15  of insulating panel  10  shown in  FIGS. 1 and 2 . Groove  15  in block  12  has a rectangular cross section. Shelf  17  has an acute angle to top surface  21 , and is substantially parallel to sheet  14  and substantially perpendicular to floor  13 . 
       FIG. 7  shows an alternative insulating panel  90 . In this embodiment, groove  92  in insulating block  95  has a triangular cross section shaped by angled shelf  94  with no groove floor and a deepest recess point  97  located where shelf  94  meets panel  91 . 
       FIG. 8  shows another embodiment, that incorporates the floor and the shelf of the groove  102  into a single concave shelf  104  in insulating block  105 . The deepest recess point  107  is located where surface  104  meets panel  101 . This produces groove  102  having a curved cross section. 
       FIG. 9  shows another embodiment  110 , in which groove  112  is formed by convex shelf  114  in block  116 . Deepest recess point  117  is located where surface  114  meets panel  111 . 
     In each of these embodiments, the groove is sized as explained in reference to  FIG. 1 . That is, a top groove and bottom groove are spaced such that they accommodate upper and lower brackets or other structures spaced apart a distance equal to or greater than the distance between the deepest recess points and less than the distance between the lips. 
       FIGS. 6-9  illustrate that there are many possible designs for the groove. So long as the groove engages the lips of a door section, the groove will be suitable for the invention. The dimensions of the insulation block, the protective sheet and the groove will vary depending on the dimensions of the door section it is to be fitted into. 
       FIG. 10  shows an alternative embodiment of the invention  150 . Insulating panel  150  is comprised of a block  154  having an interface  152  with a sheet, not shown, that is inserted into door section  156 . The block  154  of insulating panel  150  includes tabs  160  that partially cover lip  158  that form a groove adjacent the interface  152  as explained above. These tabs  160  are preferably formed from a plastic or other similarly substantially rigid material to provide strength to the engagement of the panel  150  to the door section  156 . Those skilled in the art will appreciate that some insulating materials well suited for use with the insulating block  152 , such as expanded polystyrene may be torn under stress or when rubbed against metal or other rigid materials. Tabs  160  provide strength to lips  158  to better secure attachment to a door section.  FIG. 11  shows one of the tabs  160 . Corner  162  is designed to sit flush against lip  158 . Side  164  and end  166  conform to the shape of an insulating block to snugly fit against it. Such a tab  160  is preferably, but not necessarily, attached to the insulating block by an attachment means of an adhesive, a glue, an epoxy a resin or the like, or mechanical means such as a screw, a tack or the like. Tabs may also be formed by coating a material onto the block using methods such as spraying, brushing, dipping, chemical and/or catalyst coating methods or the like.  FIG. 12  shows an alternative tab  172  covering the lip of insulating panel  170 . Tab  172  runs along the entire length of the lip to provide rigidity to the engagement with the door section and to protect the lip from breaking or tearing. Tabs  160  and  172  illustrate that it may be desirable to provide extra strength, rigidity or protection to the lip of the insulating block. Such a tab may be a separate component and made of a material such as polymer, a metal or wood or any material that provides beneficial physical characteristics to the engagement of the insulating panel to the door section into which it fits. Alternatively, such a tab may be applied as a coating of a plastic hand/or elastomeric material. Descriptions of the embodiments shown in the drawings should not be construed as limiting or defining the ordinary and plain meanings of the terms of the claims unless such is explicitly indicated. 
     Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. Descriptions of the embodiments shown in the drawings should not be construed as limiting or defining the ordinary and plain meanings of the terms of the claims unless such is explicitly indicated.