Abstract:
A reinforced garage door panel construction comprises a sandwich panel system having inner and outer skins with interconnecting insulating material, a continuous reinforcing strip extending along an inner face of the inner skin and secured to the inner face, a modified “Z” shaped structural member extending substantially the length of the panel and secured to the inner skin at the continuous reinforcing strip by fasteners which extend through the skin and into the continuous reinforcing strip, the modified “Z” shaped structural member having a web with an upstanding front flange and a depending rear flange, the depending rear flange having an inwardly extending lip extending essentially parallel to the web and the depending flange having spaced apart reinforcing beads extending the length of the depending flange.

Description:
FIELD OF THE INVENTION 
     This invention relates t reinforcement struts for use in reinforcing panel sections of interconnected panel partitions such as panel doors and in particular panel garage doors. 
     BACKGROUND OF THE INVENTION 
     Sectional panel partitions are commonly used in commercial, industrial and residential applications particularly for use as door closures. In the residential application, the sectional doors are commonly referred to as garage doors. Examples of such sectional doors are described in U.S. Pat. Nos. 3,941,180 and 3,967,671. The doors are made up of individual hingedly interconnected panels which pivot relative to one another as the door is moved from its closed position to its upward out of the way open position. Various types of interconnecting designs for the panels and related hinges are described in U.S. Pat. Nos. 4,644,725, 4,893,666, 5,002,114, 5,129,441, 5,148,850, 5,170,832 and 5,359,812 and U.K. Patent, Publication GB 2117813-A1, published Oct. 19, 1983, entitled “Connecting Wall Panels” in the name of Leonid Ostrovsky. 
     The concept of sectional portions for a door which may be cut to any width to provide a custom door design is described in the aforementioned U.S. Pat. No. 3,967,671. The basic design for a finger pinch proof interconnection of the panels is described in the aforementioned U.S. Pat. No. 3,941,180. 
     Due to the popularity of this sectional door design, there is a continuing demand to provide doors of ever increasing width and height. Although the height of the door can be accommodated by using more panels in the door build up, the width of The door is limited to some extent by virtue of its own structural integrity for each door panel. As the door width increases it is understandable that the panels can only withstand certain wind loads before their structural integrity is compromised and the panels begin to bend. In this respect various steps have been taken in the past to reinforce selected panels over the door width by use of appropriate struts. The most common type of strut is the top hat in section that is a C-section having opposing depending flanges which facilitate attachment of the strut to the selected panel. There are of course other shapes for struts which have been used in reinforcing panel doors such as the Z-shaped truss and modified C-shaped truss which accommodates a reinforcing rod at its head portion. The problem with existing strut designs however is that they are not readily installed on the door panel, require extra mounting clips or the like and do not always offer the required reinforcing characteristic to permit manufacture of door widths in excess of twenty-eight feet. These prior types of struts or trusses are mounted to the rear face of door panels by retaining clips; hence, the extent of reinforcement is determined solely by the design of The strut section. Tis type of mounting allows relative movement of the strut relative to panel inner face. It is also understood that depending upon The application, the wind load and deflection requirements will vary. It is therefore important to have a strut or truss section which can be readily adapted for a variety of applications. 
     In accordance with this invention a strut design is provided which considerably strengthens the door panel. In addition a mounting bracket which is integral with the hinge structure may be used to secure the preferred modified Z-shaped strut or any other type of strut for the door interior to reinforce same. The strut, in accordance with an embodiment of this invention, is of relative reduced weight compared to prior structures for the same wind load and deflection capacity. The struts are more readily installed and become a structural component of the door panel. Regardless of the strut size, they are installed in the same manner to minimize thereby labor error during installation. 
     SUMMARY OF THE INVENTION 
     In accordance with an aspect of the invention there is provided a reinforced garage door panel construction comprising: 
     i) a sandwich panel system having inner and outer skins with interconnecting insulating material, 
     ii) a continuous reinforcing strip extending along an inner face of said inner skin and secured to said inner face, 
     iii) a modified “Z” shaped structural member extending substantially the length of said panel and secured to said inner skin at said continuous reinforcing strip by fasteners which extend through said skin and into said continuous reinforcing strip, 
     iv) said modified “Z” shaped structural member having a web with an upstanding front flange and a depending rear flange, said depending rear flange having an inwardly extending lip extending essentially parallel to said web and said depending flange having spaced apart reinforcing beads extending the length of said depending flange. 
     In accordance with another aspect of the invention there is provided a hinge structure for interconnecting garage door panels, said hinge comprising: 
     i) first and second hinge plates interconnected by a pivot, 
     ii) said first hinge plate having an extended structural portion which extends outwardly away from a base portion of said hinge, 
     iii) said extended structural portion comprising a foot which is adapted for attachment to a structural reinforcing member for a garage door panel, 
     iv) said structural portion having a reinforcing bead extending there along towards said foot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention are shown in the drawing wherein, 
     FIG. 1 is a perspective view of he interior of a garage door. 
     FIG. 2 is a section along the lines  2 — 2  of FIG.  1 . 
     FIG. 3 is a rear elevation view of die door of FIG. 1 showing the preferred hinge structure for bracing the reinforcement strut. 
     FIG. 4 is a plan view of the modified hinge design. 
     FIG. 5 is a side elevation view of the hinge of FIG.  4 . 
     FIG. 6 is a rear elevation view of the door of FIG. 1 with the hinge of FIG. 4 mounted at a joint between two door sections, 
     FIG. 7 shows an alternative embodiment of FIG. 6 with two hinges of FIG. 4 mounted in parallel on the door rear surfaces, 
     FIG. 8 is a section through an alternative arrangement for a reinforcement strut assembly, 
     FIG. 9 is a top plan view of the strut assembly of FIG. 8, 
     FIG. 10 is a section through a door panel assembly with yet another alternative embodiment for the strut assembly, 
     FIG. 11 is a section through the door assembly with yet another alternative embodiment for the strut assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Although preferred embodiments of the invention will be described with respect to standard type of roller door having multiple sections and commonly used in garages, it is understood that the door construction may be used in any type of barrier application whether it be partitioning where the partitioning needs to be removed temporarily or in large building door installations, service garages and the like. With reference to FIG. 1 a standard door construction  10  is shown. The roller door comprises individual panels generally designated  12 . The panels are connected to one another by way of roller hinges generally designated  14  and intermediate hinges generally designated  16 . The roller hinges  14  have rollers  18  mounted on shafts which extend into standard bores in the hinges. The rollers  18  are mounted in suitable tracks  20  which receive and capture the rollers  18  and guide movement of the rollers as the door is raised. The door may be raised by any convenient door raising mechanism or may be done so manually by grasping the hole  22  on the door interior. As the door is raised the rollers  18  follow the track  20  around arcuate track portion  24  to the horizontal track portion  26  where the door is stored upwardly out of the way. To assist in raising of the door, the usual counter balance in the form of a coiled spring  28  is secured to drive rods  30  which are interconnected to cables not shown for counter balancing the weight of the door to around arcuate track portion  24  to the horizontal track portion  26  where the door is stored upwardly out of the way. To assist in raising of the door, the usual counter balance in the form of a coiled spring  28  is secured to drive rods  30  which are interconnected to cables not shown for counter balancing the weight of the door to facilitate raising from the lowered position. The horizontal track portions  26  are secured to the ceiling or other supporting structure by the usual struts  32 . Also in accordance with standard construction, the rails  20  are connected to brackets  34  which in turn are secured to plates  36 . These components are secured to the door jams to provide the necessary support. At the top for the counter balancing device, opposing plates  38  are provided which support the drive rods  30 . In addition, the counter balancing device may also be connected through plate  40  to wall bracket  42 . 
     The door is shown with the usual window opening  44 . It is understood that a variety of decorative window openings may be provided in the door panels  12 . Alternatively, the door panels may be cut out to provide an access door through the panel door. 
     As the width of the door increases the sectional panels  12  require reinforcement. In accordance with this particular embodiment, reinforcing struts  46  are provided at the intermediate height of the door as well as at the top portion of the door. The intermediate strut  46  is secured in a special manner as described with respect to FIG.  2 . The upper strut  46  is secured to the top panel of the door by way of angle brackets  48 . Although the particular arrangement of struts is for purpose of illustration, the general rule is tat depending on the wind load and deflection requirements, the struts are placed on die top and bottom panels; or on the top, bottom and every second panel; or on the top, bottom and every panel in between. 
     With reference to FIG. 2 The door panel sections  12  are shown. Each panel section  12  comprises an outer barrier wall  50  and an inner barrier wall  52 , The panels  12  may be formed in a continuous manner where the inner and outer walls  50  and  52  are joined at cold break  54  to form the respective sop edge  56  and bottom edge  58 . The material interconnecting The inner and outer walls  50  and  52  may be a polyurethane foam  60  which provides both insulative characteristics as well as adhesive characteristics to form a relatively strong yet light weight and highly insulated structure  12 . These panels may be provided in extended widths and then cut so as to provide the desired door width. All of the necessary hardware is then mounted on the panels to complete installation. As the panels are formed each panel includes an internal reinforcing strip  62  and  64  at the top and bottom of each panel to provide the necessary reinforcement for attachment devices including fasteners. 
     In this particular embodiment the top section includes a weather stripping bead of material  66  and the bottom section  58  includes weather stripping bead of material  68 . These beads of weather stripping abut the respective opposing surfaces to complete the seal of the door sections when the door is in the closed position. 
     As is common to the industry a hinge generally designated  70  is secured to the top section  56  in  6  bottom section  58  of adjacent door sectional panels. As shown in FIG. 2 the connection is made by respective fasteners  72  and  74  which pass through the inner walls  52  as well as the respective reinforcing plate  62  and  64  to complete the connection of the hinge to the respective panels. In this particular embodiment the hinge  70  has integrally formed therewith a brace generally designated  76  which extends downwardly from the hinge and is connected to the modified Z-shaped reinforcement strut  78 . Such connection is made by way of fasteners  80  extending through an angled flange portion  82  of the brace  76 . The modified Z-shaped strut comprises a folded over base flange  84  which has inner flange  86  and outer flange  88 . Extending essentially at right angles to the base flange  84  is the web  90 . Depending from the web  90  is a depending rear flange generally designated  92  with interiorally directed reinforcing lip  94 . The rear flange  92  may have corrugations or reinforcing beads such as at  96  and  98  to increase bending moment of the rear flange and thereby resist buckling of the web  90  when either an external horizontally directed force is applied to either the exterior or interior of die door. The Z-shaped strut is secured to the door interior panel by fastener  100  which also extends through the reinforcing material  62  to complete the connection which is essentially fixed subject to the shear strength of the fasteners. The Z-shaped strut is furthermore held in position by the brace  76  which further resists movement of the web in a vertical direction which as previously noted can be induced by a force applied to the door. The number of hinges  70  with corresponding braces  76  is determined by the door width although the preferred embodiment of FIG. 1 shows a single hinge with brace  76 . 
     The modified shape of the Z strut  78  enhances its structural strength but at the same time considerably reduces the amount of material used in the strut particularly compared to the standard C-shaped or top hat shaped strut. The base flange  84  of the Z-shaped strut has a folded over portion to enhance the strength of the flange as connected at spaced apart intervals (usually two feet) to the wall  52  of the door sectional panel. The web  90  extends out from the interior door face a considerable distance depending upon the extent of reinforcement required. 
     Preferably, the strut is made in a multiple of web depths so that inventory can be minimized and one need only select from 2 or 3 strut sizes to handle door widths which may vary from about 10 feet to over 45 feet. 
     The corrugations or beads  96  and  98  in the depending flange  92  greatly enhance the bending moment of the flange and thereby further resist buckling of the web  90  when the door is stressed. The provision of the lip  94  also further increases the bending moment of the flange  92  to further increase the strength of the Z-shaped section. Accordingly the Z-shaped section greatly increases door strength in resisting horizontal forces along The width of the door. By integrating the brace  76  with the hinge, the top section of each door panel is greatly strengthened to enhance bending resistance of each panel. Providing the brace  76  as an integral component of the hinge ensures that the Z-shaped suit is always held in position to enhance bucking resistance. In this respect it is understood that the hinge with integral brace may be used with other strut sections for reinforcing the door panels. For example, the hinge with integral brace could be used in combination with the standard Z-shaped strut or standard C-shaped strut. It is also understood that, by virtue of connecting, bonding, or welding the strut to the door inner panel, it is essentially fixed to form a composite reinforcing structure. Unlike the prior art which allows relative movement, the fixed relationship of the strut to door panel forms a reinforcing section which includes not only the strut, but as well the section of the panel. Hence, this composite structure offers greater bending moment with less weight compared to prior art structures. 
     With reference to FIG. 3, further benefits of the hinge design are shown. The hinge  70  has inner hinge plate  102  with depending flanges  104  located within outer hinge plate  106  which in turn has outer hinge flanges  108 . A tubular hinge pin  110  interconnects the flanges  104  and  108  to complete the hinge structure. 
     The tubular pin  110  provides the standard bore which may receive a shaft of a roller  18  used at the door edges, if required. Although, preferably, other hinge structures are used in that respect as will be described in regards to FIGS. 4 through 7. The outer hinge plate  106  includes the brace  76  integrally attached at  112  and extends rearwardly with tapered sides  114  and  116 . The brace is bent outwardly from the hinge plate  106  at break line  118 . 
     A typical roller hinge  14  is shown in FIG.  4 . The binge comprises inner hinge plate  120  and outer hinge plate  122  where the inner flanges  124  are positioned within the outer flanges  126  and interconnected by tubular hinge pin  128 . The significant benefit for the design of the hinge of FIG. 4 is that each hinge plate  120  and  122  has the apertures for the fasteners located laterally of one another and in the orientation of the hinge axes  130 . The fastener holes  132  and  134  in accordance with this particular embodiment have centres  136  parallel with the binge axes  130 . Correspondingly the apertures  138  and  140  are also aligned with the hinge axes where the apertures  138  and  140  are elongate to provide for slight adjustment in the hinge orientation during installation. This structure is superior to the prior art structures where the fastener apertures were aligned and extended transversely or at right angles to the hinge axes. By locating the fastener openings laterally of one another and parallel to the hinge axes, greater strength is achieved in the hinge connection particularly with the provision of the fastener reinforcing strips  62  and  64  at the top and bottom of each panel. As shown in FIG. 5 in addition to the tubular hinge pin  128  is a tubular roller shaft holder  142 . The distance of the holder  142  from the hinge axes varies depending upon the height at which the hinge is installed on the respective door panels. This is in accordance with standard practice where the rails slope inwardly away from the door opening to facilitate slanting of the door sections away from the door jam stops as the doors open. Suitable reinforcement by way of depressions  144  are provided in the outer flanges  126  to strengthen the flanges in carrying the roller shafts in holders  142 . Unlike prior art devices, the hinge has fixed locations for the roller pins. The hinges are manufactured to provide for location on the door, fixed roller gradations to accommodate rail slant. 
     With respect to the embodiments of FIGS. 6 and 7, the special hinges  14  are shown in plan. Due to their compact nature they may be mounted above the Z-shaped strut  78  where the hinge axes is aligned with the break  146  between the door sections  12 . In the embodiment of FIG. 6, a single hinge is mounted to the door sections. In larger installations where greater load carrying capacity is required, hinges  14  may be mounted adjacent to one another as shown in FIG. 7 where the hinge axes are aligned by the break  146  between the door sections  12 . 
     With the significant benefit of hew reinforcement strut of this invention, door widths may be greatly increased. Usually door widths in excess of 35 feet require custom design for the reinforcement struts. However with this particular strut design, multiples of the struts may be joined together in various ways to significantly increase low carrying capacity of the door system and provide for door widths greatly in excess of 35 feet and even in excess of 45 feet. By use of the strut designs of this invention greater door widths can be accommodated without appreciably increasing Me over all depth of each reinforcement smut so that head room below the retracted door is maximized. 
     With reference to FIG. 8 one embodiment of the invention for the enhanced strut design as shown, the first strut  46  is connected to the door in the normal manner as taught with respect to FIG. 2 including the use of a hinge  70  with integral brace  76 . A second strut  150  has its outer flange  152  connected to the rear flange  92  by an appropriate fastener  154 . The strut  150  is of the modified Z cross section having the web  156  with depending rear flange  158  and inwardly extending flange  160 . The rear flange  158  has the reinforcing beads  162  and  164 . Depending upon the loads to be accommodated as dictated by the wind loads and/or door width, the web  156  may be of a particular depth which can be a multiple of the depth of the web  78  of the strut  46 . In this particular embodiment the depth of the web  156  is about one half of the depth of the web  78  to thereby increase the overall moment arm of the reinforcing strut from the door inner panel  52  to the depending flange  158 . In order to stabilize the addition of the second strut to the first strut a suitable bracket  166  is provided. The bracket  166  includes a first bracket plate  168  and a second bracket plate  170 . The first bracket plate has a base  172  which is connected to the web  78  by fastener  174 . A recess  176  is formed in the plate to accommodate the thickness of flange  82  of bracket  76  and fastener  80  is used to connect the components together in the manner shown in FIG.  9 . Bracket  166  also includes upstanding arm  178  which is connected to a foot portion  180  of bracket  170  by use of fastener  182 . Foot portion  184  of bracket  170  is fastened to the web  156  by fastener  186 . In accordance with this particular embodiment as shown in FIG. 9, two fasteners  182  are used to interconnect foot  180  to the upright leg  178 . 
     With reference to FIG. 10, yet another alternative embodiment for the modified Z-shaped structural members as shown, the fist structural member  46  is connected to the inner panel  52  of the door by use of the fastener  72 . An essentially identical modified Z-shaped strut  190  is also secured to the inner panel  52  of the door by use of a pop rivet or the like  192 . The inwardly extended flanges  94  of strut  46  and  194  of strut  190  contact one another. To enhance the strength of this combination a suitable means  196  is provided for maintaining or holding die flanges  94  and  194  in contact. In This particular embodiment a plate  200  is fastened to the respective depending rear flanges  92  and  198  by fasteners  202  and  204 . Such a box structure of enlarged modulus section greatly increases the structural integrity of the door hence an installer is able to select suitable struts having the desire web depth to reinforce the door. This avoids custom forming of struts for the door and allows the installer to select form standard items which may be 2 or 3 struts of predetermined web depths. A further alternative to the embodiment of FIG. 10 is shown in FIG. 11 where not only is the section of modulus increased but as well, the moment arm. U shaped brace  206  is fastened to the depending rear flanges  92  and  198  by appropriate fasteners  208  and  210 . The U shaped brace  206  has leg portions  212  and  214  with respect of foot portions  216  and  218  which are connected with the fasteners  208  and  210 . The U shaped brace  206  maintains contact between the inwardly turned flanges  94  and  194 . It is appreciated of course that some separation may occur between the inturned flanges  94  and  194  when the system is over stressed. Due to the flexible arcuate portion  218  of the U shaped brace  206 , it is appreciated that this portion of the brace may be formed of spring steel to restrain such separation of flanges  94  and  194 . Although for most anticipated wind loads and door widths such slight separation should not compromise the over all structural integrity of the door panel system. 
     Although preferred embodiments of the invention have been described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention of the scope of the appended claims.