Patent Publication Number: US-7900681-B2

Title: Colonial storm shutter with improved strength and fabricability

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to storm shutters, and more particularly to colonial storm shutters with improved impact resistance and fabricability. 
     BACKGROUND 
     For centuries, storm shutters have been used to protect windows and doors from high winds and impacts by materials propelled by storm winds. Along the Atlantic and Gulf coasts of the United States, storm shutters are particularly important to protect against hurricanes and nor&#39;easters, and in many places are required by building codes and insurance companies. Recent hurricanes landfalls in Florida and the Gulf states have graphically demonstrated the importance of building coastal properties to withstand such storms, including providing storm shutters with sufficient mechanical strength to withstand the full force of hurricane winds. Thus, there is an urgent need for storm shutter systems with enhanced strength to withstand high winds and resist impacts from objects propelled by such winds. 
     SUMMARY 
     The various embodiments provide colonial storm shutter designs with improved impact resistance which is achieved at reduced fabrication cost and complexity. Shutter blade elements are formed with a corrugated configuration that exhibits superior structural strength and bending resistance while providing an attractive face. Triple, double and single shutter blade elements fit together in a simple overlap configuration which provides enhanced structural strength and simple assembly. Side frame structures include a reinforcing portion on the outside wall which provides increased strength and bending resistance. A storm bar includes a center storm bar clip which bolts to the side frames of two shutter panels when in the closed configuration to provide enhanced structural rigidity. Center fastening angles are attached to the side and top/bottom frames at both the top and bottom where the two shutter panels meet in the closed configuration to provide further structural strength and resistance to opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention. Together with the general description given above and the detailed description given below, the drawings serve to explain features of the invention. 
         FIG. 1  is an elevation view of a colonial shutter in a closed configuration according to an embodiment. 
         FIG. 2  is at an elevation view of a colonial shutter in a closed configuration according to a second embodiment. 
         FIG. 3  is an elevation view of a bifold colonial shutter in a closed configuration according to a third embodiment. 
         FIG. 4  is a cross-sectional view of a triple shutter blade element according to an embodiment. 
         FIG. 5  is a cross-sectional view of a double shutter blade element according to an embodiment. 
         FIG. 6  is a cross-sectional view of a single shutter blade element according to an embodiment. 
         FIG. 7  is a cross-sectional view of a side frame. 
         FIG. 8  is a cross-sectional view of a top &amp; bottom frame. 
         FIG. 9  is an end and oblique view of a center fastening angle. 
         FIG. 10  is an end and oblique view of a center storm bar clip. 
         FIG. 11  is an end and oblique view of a wall fastening angle. 
         FIG. 12A  is an end view of a storm bar. 
         FIG. 12B  is an oblique view of a storm bar assembly including a center storm bar clip. 
         FIG. 13  is a vertical cross-sectional assembly view of the storm shutter assembly illustrated in  FIG. 1  through a top portion including the center fastening angle. 
         FIG. 14  is a vertical cross-sectional assembly view of the storm shutter assembly illustrated in  FIG. 1  through a center portion including the storm bar. 
         FIG. 15  is a vertical cross-sectional assembly view of the storm shutter assembly illustrated in  FIG. 1  through a bottom portion including the center fastening angle. 
         FIG. 16  is an edge and cross-sectional view of a top portion of the storm shutter assembly illustrated in  FIG. 1  showing details of attachment to a structure. 
         FIG. 17  is an edge and cross-sectional view of a bottom portion of the storm shutter assembly illustrated in  FIG. 1  showing details of attachment to a structure. 
         FIG. 18  is a horizontal cross-sectional assembly view of a top portion of the storm shutter assembly illustrated in  FIG. 1 . 
         FIG. 19  is a horizontal cross-sectional assembly view of the middle portion of the storm shutter assembly illustrated in  FIG. 1 . 
         FIG. 20  is a horizontal cross-sectional detail view of an attachment portion of bar and storm shutter assembly illustrated in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes and are not intended to limit the scope of the invention or the claims. 
     As used herein, the terms “about” or “approximately” for any numerical values or ranges indicates a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein. As used herein, the terms “fastener” and “mechanical fastener” are intended to encompass all known devices, methods and materials used for attaching two or more components together, including but not limited to any one or combination of the following: threaded bolts, threaded bolts with nuts, screws, pin, rivets, pop rivets, welding, nails, adhesives and equivalents thereof. Further, references herein to “fastener” are not intended to limit the scope of the invention or the claims to the type or arrangement of example fasteners illustrated in the drawings unless a particular type of fastener is specifically recited in the claims. 
     The various embodiments provide a storm shutter design which is capable of withstanding the high wind and large impact load expected from large huricanes. Shutter blade elements are formed with a corrugated configuration that exhibits superior structural strength and bending resistance while providing an attractive face. Triple, double and single shutter blade elements fit together in a simple overlapping configuration which provides enhanced structural strength and simple assembly. Side frame structures include a reinforcing portion on the outside wall which provides increased strength and bending resistance. An “L” shaped storm bar includes a center storm bar clip which bolts to the side frames of two shutter panels when in the closed configuration to provide enhanced structural rigidity. Center fastening angles are attached to the side frame at both the top and bottom of each of the two shutter panels when in the closed configuration to provide further structural strength and resistance to opening. The storm shutters according to the various embodiments are easy to assemble, requiring fewer assembly steps and fastener installations. The storm shutters according to the various embodiments are also easy to deploy into the closed configuration requiring the attachment of only a few parts with simple machine bolts. 
       FIG. 1  provides an elevation view of an embodiment storm shutter assembly attached to a structure in the closed configuration. In the embodiment illustrated in  FIG. 1 , the storm shutter assembly includes two shutter panels  2  attached by hinges  6  on either side of an opening in a structure, such as a window or door. In the open configuration (not shown), each of the two shutter panels  2  fold back over the structure about hinges  6 , thereby framing the window or door in the conventional manner well known to colonial storm shutters. To position the shutter panels  2  in the closed configuration illustrated in  FIG. 1 , each shutter panel  2  is pivoted about the hinges  6  to the closed position where the two panels nearly touch. A storm bar  10  is positioned in front of the shutter panels  2  and attached to the structure (as illustrated in  FIG. 1  and described in more detail below) or to the outside shutter panel side frames  4  (as illustrated in  FIG. 2  and described in more detail below). A center storm bar clip  19 , which is attached to the middle of the storm bar  10 , is bolted to the inner shutter panel side frames  4  with machine bolts  14  which thread in two rivnuts  15  as described in more detail below with reference to  FIG. 14 . A center fastening angle  12  is then bolted to the inner shutter panel side frames  4  at the top and bottom of the shutter with machine bolts  14  which thread into rivnuts  15  as described in more detail below with reference to  FIGS. 13 and 15 . So configured, the storm shutter is now prepared to endure hurricane strength winds and associated debris hits. 
     Each shutter panel  2  is formed from two side frames  4  joined at the top and bottom to top and bottom frames  3  which together hold in place a plurality of shutter blade elements  1  which span the opening between the side frames. The side frames  4  are joined to the top and bottom frames  3  in miter joints which can be secured in part by hinges  6  coupled with mechanical fasteners  13  such as rivets or pop rivets. In particular, the hinges  6  are positioned at the top and bottom of each shutter panel and configured so the shutter-side portion of the hinge  6  is attached by mechanical fasteners  13  to both the bottom or top frame  3  and the adjoining side frame  4 , thereby providing a structural connection between the two members. In an embodiment, each hinge  6  is attached to the side (and at the top and bottom also to the top and bottom frames  3 ) by four mechanical fasteners  13 , such as rivets. Using four fasteners  13  instead of the customary two fasteners provides increase structural strength. Also, in an embodiment using four fasteners  13  to attach the shutter-side portion of the hinges  6  at the top and bottom corners of the shutter panels  2 , enables the hinges  6  to be attached so that two fasteners  13  engage the side frame  4  and two fasteners  13  to engage the top or bottom frame  4 , thereby using the hinge bases as a strap to further connect the side frame  4  to the top and bottom frames  3 . 
     As described in more detail below, either end the shutter blade elements  1 A,  1 B,  1 C (which are illustrated in  FIGS. 4-6 ) fit within the open side of the side frames  4  with the shutter blade elements  1 A,  1 B,  1 C extending horizontally between the two side frames  4 . As described more fully below, the various shutter blades  1 A,  1 B,  1 C overlap to provide a continuous structure extending between the top and bottom frames  3 . The shutter blade elements  1 A,  1 B,  1 C held in place by fitting closely within the side frame  4  structure. At selected intervals along the side frames  4 , such as at 16 inch spacing (approx.), shutter blade elements  1 A,  1 B,  1 C may be further secured to the side frames  4  by mechanical fasteners  13 , such as rivets or pop rivets. 
       FIG. 1  shows some of the features which provide the storm shutter assembly with enhanced structural strength. Each of the shutter panels  2  exhibit exceptional structural strength due in part to the unique structure for the shutter blades  1  and side frames  4  which are described below with reference to  FIG. 4  and  FIG. 7 . Additionally, the storm shutter assembly hinges  6  are positioned at the top and bottom corners, center fastening angles  12  bolted to the top and bottom of the inner side frames  4  where the two shutter panels  2  meet, and a center storm bar  10  including a center storm bar clip  19  bolted to the center portion of the inner side frames  4  where the two shutter panels  2  meet combine to reinforce the structural strength of the shutter panels when the assembly is in the closed position. Further strength is provided by using four mechanical fasteners  13  (e.g., rivets) to attach each hinge  6  to a side frame  4  instead of the conventional practice of using only two fasteners. 
     An optional design embodiment concerns the attachment of the storm bar  10  to the building or shutter assembly. In one embodiment illustrated in  FIG. 1 , the storm bar is attached to the building by a wall fastening angle  11  on either side of the storm shutter assembly. In an alternative embodiment illustrated in  FIG. 2 , the storm bar  10  can be attached to the outer side frame  4  with a machine bolt  14  which threads into a rivnut  15  positioned within the side frame  4  as described more fully below with reference to  FIG. 20 . With the exception of the storm bar attachment, the embodiment illustrated in  FIG. 2  is substantially the same as that described above with reference to  FIG. 1 . 
     The various embodiments can be configured and sized to fit a wide variety of building openings and be attached to a variety of building materials, including wood frames and cement block. For example, the storm shutter embodiment illustrated in  FIG. 1  is sized to fit a 48″×72″ window opening, while the example bifold storm shutter embodiment illustrated in  FIG. 3  can be sized to fit a 96″×112″ window or sliding glass door opening. This wide range of size compatibility is achieved without the need for different components, since the side frames  4 , top and bottom frames  3 , shutter blades  1  and storm bars  10  are all extruded aluminum pieces of fixed cross-sections that can be cut to length. Thus, a single colonial storm shutter design can be adapted to practically any size building opening and achieve the same level of structural integrity without the need for a plurality of different components or installation configurations. 
     Referring to  FIG. 3 , a bifold shutter assembly includes shutter-to-shutter hinges  20  between two shutter panels  2  to form a bifold assembly. In this manner, a bifold assembly having an attractive width when in the open configuration, such as 28″ as in the case of a 112″ wide bifold shutter assembly, can span the full width of a large opening. Each of the shutter-to-shutter hinges  20  are attached to a side frame  4 , and in the case of the top and bottom corners also to the top or bottom frame  3 , with four mechanical fasteners  13 . When deployed in the closed configuration, with the center-most shutter panels  2  mechanically coupled by the center storm bar clip  19  and center fastening angles  12 , the shutter assembly forms a near rigid structure extending between the wall mounting hinges  6 , with additional reinforcement provided by one or more storm bars  10 . In the 96″×112″ bifold shutter assembly illustrated in  FIG. 3 , three storm bars  10  may be used to provide reinforcing over the entire width and height of the storm shutter assembly. As a option for strengthening the bifold shutter assembly, each storm bar  10  can also be bolted to each side frame  4  using machine bolts  14  engaged into rivnuts  15  secured in the side frames  4  in the same manner as the rivnuts  15  used to connect the center storm bar clip  19 . 
     Referring to both  FIG. 1  and  FIG. 3 , the various embodiments make use of the hinge  6 ,  20  attachments and center fastening angle  12  to provide additional structural connections between the top or bottom frame  3  and adjoining side frame  4 . Using four mechanical fasteners  13  (such as rivets or pop rivets) which engage both the top or bottom frame  3  and adjoining side frame  4  to connect the hinges  6  to each shutter panel  2  provides a rigid structural connection between the frame pieces. Similarly, the use of the center fastening angle which bolts into both the top or bottom frame  3  and the adjoining side frame  4  provides a rigid mechanical connection between these two structures when in the closed configuration. Thus, the use of these structures in combination with the reinforced miter joints securely fastens the frame members together while eliminating the need for other structural connecting/reinforcing hardware. These design elements reduce hardware costs and inventory, and eliminates assembly steps, thereby reducing the overall cost of the storm shutter assembly while enhancing overall structural strength. 
     The shutter blades  1  can be configured in triple blade, double blade and single blade elements  1 A,  1 B,  1 C (as illustrated in  FIGS. 4-6 ) to facilitate assembling storm shutters to fit various size window and door openings. In a preferred embodiment, the triple blade, double blade and single blade elements are formed of extruded aluminum having a nominal wall thickness of approximately 0.062 inches. 
       FIG. 4  shows a cross-section of the triple blade element  1 A according to a preferred embodiment. The shutter blades are configured with a unique corrugated profile which provides enhanced structural performance while providing an attractive front when in the open configuration. The corrugated profile includes a repeating pattern of surfaces which from the front side in the open configuration appears as a series of canted blades. In particular, the corrugated profile features a vertical underlap portion  40  connected at approximately a right angle to a first horizontal portion  42  which connects at approximately a right angle to a first front vertical cantilever portion  44 . A first diagonal portion  48  connects to the first horizontal portion  42  at an acute angle  43  and to the first front vertical cantilever portion  44  at an obtuse angle  45  on one end and to a first back vertical portion  52  on the other end at an obtuse angle  50 . In a preferred embodiment, the horizontal portion-to-diagonal portion acute angle  43  is about 45°, the front vertical portion-to-diagonal portion obtuse angle is about 135° and the diagonal portion-to-back vertical portion obtuse angle  50  is about 135°. On the free end of the front vertical cantilever portion  44  is formed a radiused portion  46 . In a preferred embodiment, the radiused portion  46  has a radius of approximately 0.062 inches. 
     In the triple blade element  1 A, the corrugated profile continues with the first back vertical portion  52  connecting at approximately a right angle to a second horizontal portion  42   a  which connects to a second front vertical cantilever portion  44   a  and a second diagonal portion  48   a  which connects to a second back vertical portion  52   a . Similarly, the second back vertical portion  52   a  connects at approximately a right angle to a third horizontal portion  42   b  which connects to a third front vertical portion  44   b  and a third diagonal portion  48   b . The third diagonal portion  48   b  connects at an obtuse angle to a vertical back joint transition portion  54 . The joint transition portion  54  adjoins to a vertical overlap portion  56  which is thinner than the joint transition portion  54  leaving a vertical gap  58 . The vertical overlap portion  56 , vertical gap  58  and joint transition portion  54  are configured so that the vertical underlap portion  40  of an adjoining blade element will fit into the vertical gap  58  so that the back surfaces of the joint transition portion  54  and the underlap portion  40  are approximately parallel. 
       FIG. 5  shows a cross-section of the double blade element  1 B according to a preferred embodiment. The double blade element  1 B features the same corrugated profile as described above with reference to  FIG. 4  with the exception that there are only two blade patterns (i.e., two horizontal portions  42 ,  42   a , two vertical front cantilever portions  44 ,  44   a  and two diagonal portions  48 ,  48   a ). With the exception of the overall length, the shapes and dimensions of the double blade element  1 B are substantially the same as those of the triple blade element  1 A. 
     Similarly,  FIG. 6  shows a cross-section of the single blade element  1 C according to a preferred embodiment. The single blade element  1 C features the same corrugated profile as described above with reference to  FIG. 4  with the exception that it includes only a single blade pattern (i.e., one horizontal portion  42 , one vertical front cantilever portion  44  and one diagonal portion  48 ). Also, the back vertical portion  52  is the same as the joint transition portion  54 . With the exception of the overall length, the shapes and dimensions of the single blade element  1 C are substantially the same as those of the triple blade element  1 A. 
     In a preferred embodiment, the triple, double and single blade elements  1 A,  1 B,  1 C have the dimensions shown in  FIGS. 4-6 . In particular, in the preferred embodiment the horizontal portion  42  of the blade elements is sized so that the front surface of the front vertical cantilever portion  44  and back surfaces of the vertical underlap portion  40  and the back vertical portion  52  are approximately 1.125 inches apart which defines the depth of the cantilever blades  1 . Further, in the preferred embodiment the triple blade element  1 A is approximately 6.560 inches in total width, the double blade element  1 B is approximately 4.56 inches in width, and the single blade element is approximately 2.56 inches in width, with horizontal portions  42  separated by approximately 2.0 inches. The length of the triple, double and single blade elements  1 A,  1 B,  1 C depends upon the size of the window or door opening. For example, a storm shutter according to the embodiment illustrated in  FIG. 1  configured to span a 48 inch window includes two shutter panels  2  that are about 24 inches wide, each including triple, double and single blade elements  1 A,  1 B,  1 C that are about 21.5 inches in length. 
     In an embodiment, the joint transition portion  54  is approximately twice the thickness of the rest of the triple blade element  1 A, and in a preferred embodiment, the joint transition portion  54  is approximately 0.132 inches thick. In an embodiment, the vertical overlap portion  56  and vertical gap  58  are approximately equal to the thickness of the rest of the triple blade element  1 A, and in a preferred embodiment, the vertical overlap portion  56  is approximately 0.062 inches thick and the vertical gap  58  is approximately 0.07 inches in thickness and approximately 0.5 to 4 inches in length. So configured, adjacent blade elements can fit smoothly together to present an even blade pattern on the shutter panel  2 , while providing increased structural strength at the point of joining without the need for additional fasteners or attachment structures. By eliminating the need for interlocking, welding, riveting or otherwise joining adjacent blade elements (as is the norm in conventional storm shutters), assembly is facilitated since adjacent blade elements can simply be slid together as they are inserted into the side frames  4 . 
     While the dimensional values for the triple, double and single blade elements  1 A,  1 B,  1 C shown in the figures and described above reflect those of a preferred embodiment, they are not intended to limit the scope of the invention or the claims. Shutter blade elements with different blade profiles characterized by different dimensional values as may be used without departing from the scope and spirit of the present invention. 
     The innovative corrugated profile of the triple, double and single blade elements  1 A,  1 B,  1 C provides high bending strength with relatively thin material cross-section. For example, the configuration of the back vertical portion  52  and front vertical cantilever portion  44  connected to the horizontal portion  42  provides bending strength characteristics similar to those of an I-beam, while the diagonal portion  48  resists torsional loads and distributes pressures applied to the back vertical portion  52 . By employing the corrugated profile shown in  FIGS. 4-6 , the blade elements eliminate the need for a solid back plane structure as used in most conventional shutter designs, thereby reducing weight and material costs. As a consequence of the corrugated blade design, the shutter blades  1  are able to withstand high impact forces without failure, distributing such forces to the side frames  4 . Further, the design of the triple, double and single blade elements  1 A,  1 B,  1 C provides approximately equal bending strength in both directions perpendicular to the shutter blade plane (i.e. parallel to the horizontal member  42 ) so that the shutter blades  1  are effective in resisting both positive and negative pressures as may be experienced in severe weather. Being extruded as a single pieces, the triple, double and single blade elements  1 A,  1 B,  1 C are also affordable to manufacture, and due to the non-interlocking underlap/overlap joints between blade elements, the blade elements are simple to assemble, thus reducing assembly costs. 
       FIG. 7  is a cross-sectional view of the side frame  4 . The side frame  4  is preferably an extruded aluminum beam with a wall thickness of approximately 0.085 inches in the form of a H with one end closed. More particularly, the side frame  4  includes a first wall  71  and a second wall  72  separated by a perpendicular center wall  73  and an outer wall  77 . The space between the first and second walls  71 ,  72  and the perpendicular center wall  73  forms an opening  74  into which the shutter blades  1  can fit. In a preferred embodiment, the opening  74  has a width of approximately 1.152 inches, which is just slightly larger than the 1.125 inch (approx.) depth of the shutter blades  1 . Within the outer wall  77  is provided a thicker reinforcing portion  79  which is approximately centered in the outer wall  77  and runs the entire length of the side frame  4 . In an embodiment, this reinforcing portion  79  is approximately twice the thickness of the rest of the side frame  4  structure, and in a preferred embodiment, the reinforcing portion  79  is approximately 0.176 inches thick compared to the rest of the outer wall  77  which is approximately 0.085 inches thick. The thicker reinforcing portion  79  provides greater strength to the side frames  4 , particularly in the miter joint where holes are drilled for attachment screws or bolts which thread into the screw bosses  86 ,  89  in the top and bottom frames  3  (see  FIG. 8 ). The extra thickness in the reinforcing portion  79  allows the holes to be countersunk to provide a flush finish when the miter joints are assembled. 
       FIG. 8  is a cross-sectional view of the top/bottom frames  3 . The top and bottom frame  3  is preferably an extruded aluminum beam with a wall thickness of approximately 0.085 inches in the form of a box with extended legs. More particularly, the top/bottom frame  3  includes a first wall  81  and a second wall  82  separated by a perpendicular center wall  83  and a top/bottom wall  87 . The space between the first and second walls  81 ,  82  and the perpendicular center wall  83  forms an opening  84  into which the shutter blades  1  can fit. In a preferred embodiment, the opening  84  has a width of approximately 1.152 inches, which is just slightly larger than the 1.125 inch (approx.) depth of the shutter blades  1 . Within the perpendicular center wall  83  may be provided a first semi-cylindrical screw boss  86  which is approximately centered on the perpendicular center wall  83  and runs the entire length of the top/bottom frame  3 . Within the top/bottom wall  87  may be provided a second semi-cylindrical screw boss  89  which is approximately centered in the top/bottom wall  87 , provided on a spine  88  and runs the entire length of the top/bottom frame  3 . When the miter joints are assembled, machine screws are passed through holes drilled in the ends of the outer walls of the side frames  4  and threaded into the screw bosses  86 ,  89 . 
     As mentioned above, one of the key structural elements of the overall shutter assembly is the center fastening angle  12 , details of which are illustrated in  FIG. 9 . This fastener can be a simple “L” shaped piece with pre-drilled holes  91  through which machine bolts  14  can pass in order to couple the center fastening angle  12  to the side frame  4  and top/bottom frame  3  of the shutter panels  2  as described in more below with reference to  FIGS. 13 and 15 . In a preferred embodiment, the center fastening angle  12  is approximately 0.125 inches thick with a height of about 3 inches, a horizontal extension width of about 1.5 inches and a length of about 3 inches. Using an “L” shaped fastener provides a very rigid structure using less material since the horizontal extension resists bending stress applied to center fastening angle  12 . 
     Similarly, as shown in  FIG. 10 , the center storm bar clip  19  is preferably a simple “L” shaped piece with predrilled holes  103  through which machine bolts  14  can pass in order to couple it to the side frame  4  of shutter panels  2  as described below with reference to  FIG. 14 . The center storm bar clip  19  also includes through-holes  104  in the horizontal extension portion through which mechanical fasteners  13  can be used to couple the center storm bar clip  19  to the storm bar  10  as described below with reference to  FIGS. 12B and 14 . In a preferred embodiment, the center storm bar clip  19  is made of aluminum with a thickness of approximately 0.125 inches, with a height of about 3 inches, a horizontal extension width of about 2 inches, and a length of about 3 inches. 
     As shown in  FIG. 1  and discussed in more detail below with reference to  FIG. 18 , the storm bar  10  may be attached to the building structure when the storm shutter is in the closed configuration.  FIG. 11  shows details of a wall fastening angle  11  suitable for accomplishing this attachment. The wall fastening angle  11  may be a simple “L” shaped piece with predrilled bolt holes  111  for bolting the wall fastening angle  11  to the storm bar  10  and to the building structure. In an embodiment, the wall fastening angle  11  is made of 0.125 inch thick aluminum with a height dimension (i.e., short leg length) of about 2 inches, a width dimension (i.e., long leg length) of about 4 inches and a length of about 3.34 inches (˜3⅞ inches). Attachment of the wall fastening angle  11  to the storm bar  10  and building structure are described below with reference to  FIG. 18 . 
     The storm bar  10  enhances the strength of the storm shutter assembly in the closed configuration by distributing loads applied to the inner side frames  4  applied to the center storm bar clip  19  to the building and working in combination with the upper and lower center fastening angles  12  to keep the shutter panels  2  closed.  FIGS. 12A and 12B  show details of the storm bar configuration according to preferred embodiment. The storm bar  10  may be configured as an “L” shaped beam, however, other configurations may be utilized, including square or triangular channel beams. In a preferred embodiment the “L” shaped beam is formed from 0.25 inch thick aluminum with a height dimension (i.e., length of the vertical leg  121 ) of about 2 inches and a width dimension (i.e., length of the horizontal leg  122 ) of about 3 inches. The storm bar  10  may be fabricated by extrusion, or from aluminum plate, such as by bending or welding to form the “L” shape. The center storm bar clip  19  is joined to the storm bar  10  by mechanical fasteners, such as bolts or rivets  123 , or by welding (not shown). Through holes  124 ,  125  may be drilled in the storm bar  10  for accommodating bolts for attaching the wall fastener angle  11  as described below with reference to  FIG. 18 , or for attaching the storm bar  10  directly to shutter side frames  4  as described below with reference to  FIG. 20 . The full length “L” of the storm bar  10  depends upon the size of the structure opening covered by the storm shutter. For example, in the embodiment illustrated in  FIG. 1  in which the storm shutter assembly is 48 inches wide, the storm bar  10  may be about 56-57 inches in length, while in the bifold embodiment illustrated in  FIG. 3 , the storm bars  10  may be about 120-121 inches in length. 
     Details regarding assembly of the top portion of shutter panels  2  and attachment of the center fastening angle  12  are illustrated in the cross-sectional view shown in  FIG. 13 . The shutter panel is formed by fitting shutter blades  1  into the opening  74  in the side frame  4 . At intervals, the shutter blades  1  may be fixed to the side frame  4  by a mechanical fastener  13 , such as rivets or pop rivets. At the top of the shutter panel, a top frame  3  is fitted over the shutter blades  1  and attached to the side frames  4 . To provide a threaded receptor for machine bolts  14  used to attach the center fastening angle  12  to the shutter panel  2 , rivnuts  15  may be positioned in the top frame  3  and side frame  4 . Rivnuts  15 , which are well-known in the industry, are metal inserts that provide a female fastener which are positioned in a pre-drilled hole and then expanded like a rivet to form a threaded attachment point secured to the structure. The interior of the rivnut  15  is threaded to accommodate a bolt  14 . The center fastening angle  12  can then be attached to the shutter panel  2  by passing machine bolts  14  through the predrilled holes  121  in the center fastening angle  12  and threading them into the rivnuts  15 .  FIG. 13  also illustrates how in a preferred embodiment the shutter assembly is sized to overlap building structure  30 , such as by ⅝ inch, to ensure proper protection for the window. 
     Details regarding assembly of the center portion of shutter panels  2  and the attachment of the center storm bar clip  19  are illustrated in the cross-sectional view shown in  FIG. 14 . As discussed above, the shutter panel  2  is formed by fitting shutter blades  1  into the opening  74  in the side frame  4 . To provide a threaded receptor for machine bolts  14  for attaching the center storm bar clip  19 , rivnuts  15  may be positioned in the side frame  4 . The center storm bar clip  19  can then be attached to the center portion of the storm shutter assembly by threading machine bolts  14  through the predrilled holes  103  in the center storm bar clip  19  and into the rivnuts  15 .  FIG. 14  also illustrates how the center storm bar clip  19  can be attached to the storm bar  10  by mechanical fasteners  13  (such as rivets as illustrated or nuts and bolts) positioned in the pre-drilled holes  104  of the center storm bar clip  19  and in the storm bar  10 . As can be seen in  FIG. 14 , attaching the center storm bar clip  19  with machine bolts  14  to the side frame  4  rigidly attaches the strong storm bar  10  to the shutter panel  2 , thereby providing structural reinforcement for the center portion of the storm shutter assembly. 
     Details regarding assembly of the bottom portion of shutter panels  2  and the attachment of the center fastening angle  12  are illustrated in the cross-sectional view shown in  FIG. 15 . At the bottom of the shutter panel, a bottom frame  3  is fit over the shutter blades  1 . To provide a threaded receptor for machine bolts  14 , rivnuts  15  may be positioned in the bottom frame  3  and side frame  4 . The center fastening angle  12  can then be attached to the storm shutter assembly by passing machine bolts  14  through the predrilled holes  121  in the center fastening angle  12  and threading them into the rivnuts  15 . 
     Details regarding attachment of the top portion of the shutter panels  2  to building structure are illustrated in  FIG. 16  and details regarding attachment of the bottom portion of the shutter panels  2  to building structure are illustrated in  FIG. 17 . Further details of the attachment of the shutter panels  2  to building structure  30 ,  32  are illustrated in  FIG. 18 , which is a cross-sectional view representative of both the top and bottom portions of the shutter panel. Referring to  FIGS. 16-18 , each of the shutter panels  2  are attached to a building structure by a plurality of hinges  6 , such as by means of lag screws  17  for mounting the hinges upon wooden frames, masonry anchors such as Tapcons®  16  for mounting the hinges upon masonry frames, or other mechanical attachments. The lag screws  17  may be driven directly into a wood window frame as illustrated on the left hand portion of  FIG. 18 , while Tapcons®  16  may be driven directly into concrete structure as illustrated in  FIGS. 16 ,  17  and the right hand portion of  FIG. 18 . In a preferred embodiment, lag screws  17  used to mount hinges  6  to wood window frames  32  are inserted a minimum of 2½ inches, and Tapcons®  16  mounting hinges  6  to masonry frames  30  are inserted a minimum of 1¼ inches. In a preferred embodiment, the lag screws  17  or Tapcons®  16  are spaced about 2 inches apart in the building-side of the hinges  6 . 
       FIGS. 16-18  also show how the shutter-side portion of the hinge  6  can be attached to the shutter side frame  4  by mechanical fasteners  13 , such as rivets or pop rivets. 
       FIG. 18  also provides another view showing how the shutter blades  1  are positioned within the openings  74  within the side walls  4 , and another view of the details for attaching a center fastening angle  12  to the shutter side frames  4  by machine bolts  14  threaded into rivnuts  15 . 
       FIG. 19  provides a cross-sectional view of the center portion of the shutter assembly showing additional details regarding the attachment of the storm bar  10  to shutter panels  2  and building structure  30 ,  32 .  FIG. 19  shows how the storm bar  10  can be attached to building structure  30 ,  32  in the embodiment illustrated in  FIG. 1 . Specifically, the wall fastening angle  11  can be attached to the storm bar  10  by fasteners such as nuts and bolts  18 , and the wall fastening angle  11  can be attached to the building structure  30 ,  32  by a wingnut and threaded fastener  8 . The wingnut and threaded fastener  8  includes a threaded fastener which is driven into the building structure  30 ,  32  leaving exposed a threaded portion which matches the threads of the wingnut. Commercially available threaded fasteners  8  suitable for use in an embodiment are marketed by Elco®, an Acument Global Technologies Company, under the trademark PanelMate®. In this embodiment, the storm bar  10  can be is attached to the structure simply by positioning the wall fastening angle  11  over threaded fastener portion attached to the structure and threading on a wingnut.  FIG. 19  also shows again how the shutter blades  1  are positioned within the openings  74  within the side walls  4 , and how the center storm bar clip  19  is attached to the center portions of the shutter panels  2  by machine bolts  14  threaded into rivnuts  15  mounted within the side frames  4 . 
     In an alternative embodiment illustrated in  FIGS. 2 and 20 , the storm bar  10  can be attached to the outer side frames  4  by a machine bolt  14  positioned in the through hole  123  in the storm bar  10  shown in  FIG. 12B  and threaded into a rivnut  15  attached to the side wall  4 .  FIG. 20  provides a detailed cross-sectional view of this attachment viewed from beneath the storm bar  10 . 
     The various embodiments described above provide a strong shutter design which is easily assembled. In an embodiment, the shutter panels can be assembled as follows. A bottom frame  3  can be attached to two side frames  4  by drilling holes in the outer walls  77  near the ends of the two side frames  4 , passing machine screws through these holes and threading them into the screw bosses  86 ,  89  in the bottom frame  3 . As discussed above with reference to  FIG. 7 , these holes are drilled through the thicker reinforcing portion  79  of the side frames  3 , and thus can be countersunk so the screws are flush when installed without compromising the strength of the outer wall  77 . With the side and bottom frames assembled, triple blade elements  1 A can be slide into the openings  74  within the side frames  4  from the top end of the frames until the height of the shutter panel  2  is filled. To accommodate different size shutters, double or single blade elements  1 B,  1 C can be included in the shutter panels  2 . Since the triple, double and single blade elements  1 A,  1 B,  1 C simply overlap and do not include interlocking pieces, the assembly of the blade elements can proceed quickly. When the full height of the side frames  4  has been filled with triple blade, double blade and/or single blade elements  1 A,  1 B,  1 C, a top frame  3  can be attached to the two side frames  4 . Again, the miter joints are assembled by passing machine screws through holes drilled in the ends of the outer walls  77  of the side frames  4  and threading them into the screw bosses  86 ,  89  within the top frame  3 . Hinges  6  are then attached to one side frame  4  at the top and bottom corners and at intervals there between. At the top and bottom corners, the shutter-side of the hinges  6  are attached to both the top/bottom frame  3  and side frame  4 . At intervals along the length of the side frames  4 , such as approximately every 16 inches, mechanical fasteners  13  (such as pop rivets) are used to attach the shutter blades  1  to the side frames  4 . Finally, rivnuts holes are drilled in the side frames  4  and top/bottom frames  3 , and rivnuts  15  are inserted and expanded in order to form a proper mechanical fit within the frames. At this point, the shutter panel  2  is ready for assembly on a structure. Shutter panels may be painted or coated with protective materials before or after assembly. This simple assembly process and reduced material count reduces the cost of manufacturing the storm shutters. 
     To install shutter assemblies on buildings, contractors merely need to attach the hinges  6  to the opening frame in the structure such as by using lag screws  17  or Tapcons®  16  (as appropriate). When installing the embodiment illustrated in  FIG. 1 , the wingnuts and threaded fasteners  8  are also driven into the structure at the centerline of the window or door opening to accommodate the storm bar. This simple attachment process reduces the cost of installing the storm shutters. 
     To position the storm shutters in the closed configuration, the shutter panels  2  on either side of the window or door are pivoted about the hinges  6  into the closed position. Center fastening angles  12  are attached at the bottom and top of the storm shutter by threading machine bolts  14  through the holes  91  in the center fastening angles  12  and into the rivnuts  15  within the side frames  4  and bottom/top frames  3 . The storm bar  10  is attached either to the side frames  4  by machine bolts  14  threaded into rivnuts  15  within the side frames  4  (for the embodiment shown in  FIG. 2 ) or to the structure by positioning the wall fastening angle  11  over threaded faster portion attached to the structure and threading on a wingnut  8  (for the embodiments shown in  FIGS. 1 and 3 ). The center storm bar clip  19  is attached to the inner side frames  4  by threading machine bolts  14  through the holes  103  in the clip and into the rivnuts  15  within the side frames  4 . No further assembly steps are required. This simple deployment process allows home and business owners to deploy their storm shutters more quickly than is the case with conventional storm shutters, and thereby provide more time for them to evacuate if needed. In the case of an average sized home, this simple installation process can save typical home owners two to three hours, which can be significant when evacuation is required. 
     In a preferred embodiment all of the aluminum components (e.g., shutter blade elements  1 A,  1 B,  1 C, top/bottom frames  3 , side frames  4 , hinges  6 , storm bar  10 , wall fastening angle  11 , center fastening angle  12 , and center storm bar clip  19 ) can be made from Aluminum 6063-T5. However, other materials may be used, such as other aluminum alloys and higher strength materials as would be appreciated by one of skill in the art. 
     The foregoing description of the various embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, and instead the claims should be accorded the widest scope consistent with the principles and novel features disclosed herein.