Patent Application
20190323282
The present disclosure relates to reinforcing struts for door panels and more particularly, to struts for garage doors designed to withstand high wind loads.
Doors for garages, loading bays, warehouses and other structures that accommodate the passage of vehicles and people generally have a large exposed surface area. Such doors are subject to significant forces during high wind events. When these forces exceed the strength of the door, the door may fail, allowing wind and rain to enter the garage and attached structures. This can lead to water damage and to structural damage because of overpressure. Building codes in regions where high wind conditions are more common, for example, the Southeastern United States, typically require that garage doors be certified to meet or exceed a specified wind load. Insurers may also require that large area doors meet wind load requirements in order to insure a structure against wind damage.
Typically, garage doors are formed from a series of panels connected to one another by hinges. These panels may be formed from rolled or stamped sheets of metal creating so-called “pans.” Panels may also be formed from an embossed metal skin surrounding a thermally insulating foam core. To make the panels stronger requires using thicker metal components that are generally heavier and more costly.
Instead of strengthening the panels themselves to withstand wind load forces, one or more struts are connected to the panels. These struts may be connected to the inside surface of the panels forming the door and extend horizontally across the width of the panel. The struts are typically made from a steel sheet roll formed into a U-shape so that the legs of the “U” are perpendicular to the inner surface of the door panel. The strut resists bending in response to forces applied normal to the surface of the door by wind and/or differences in air pressure inside and outside the door.
In general, the strength of known struts depends on the length of the legs of the “U” forming the strut, the type of material used to form the strut, and the thickness of the material. To provide sufficient strength against winds encountered in heavy storms, thicker and/or larger struts are used. In addition, to achieve the required strength, additional struts may be added to one or more of the panels forming the door. Using large or thicker struts or adding additional struts increases the material cost and adds complexity to door manufacturing.
Strengthening door panels by adding thick or larger struts may also increase the weight of the door, making the door more difficult or more expensive to operate. Typically, to assist a user in manually lifting a garage door, one or more counter balance springs are provided to bias the door in the upward direction. Heavier doors may require springs capable of providing higher forces. Under some circumstances, heavier springs add expense to the door mechanism. In addition, in many cases garage doors are equipped with motorized door opening mechanisms. These devices are activated to open and close by a transmitter in the user's vehicle and/or by a wall switch inside the garage using an electric motor. Heavier doors may require more energy to operate.
Larger struts may also impact the usable space within the garage. Typically, garage doors engage with tracks located on either side of the doorway. Rollers connected with the door panels engage with these tracks to guide the door as it opens and closes. In many garages, the tracks extend vertically along the sides of the doorway and then bend into the horizontal direction so that the door panel is parallel to the ceiling of the garage when the door is open.
When the door is open, struts connected with the inside surface of the door panels extend downward. The distance the struts extend downward from the open garage door may determine the headroom available inside the garage. To achieve sufficient strength to resist windloads may require using taller struts that limit the headroom, preventing larger vehicles, for example, large sport utility vehicles and vehicles with roof racks from fitting in the garage.
Using multiple struts on a door panel to achieve a given strength may not be practical. Garage doors often include windows to admit light into the garage and create an architecturally pleasing arrangement. Windows are located on one or more of the door panels. Generally, it is not desirable to extend a strut across a window because this blocks light and the portion of the strut visible through the window may be unsightly. Thus, at least for door panels with windows, it may be undesirable to add additional struts and instead larger, heavier struts may be required to provide sufficient strength to door panels including a window.
Thus, there is a need for an improved strut for wind load doors such as Sectional garage doors that provides sufficient strength to withstand a given wind load that uses less material, is of lighter weight, and allows greater headroom below the surface of the open door than is provided by known struts.
The present disclosure relates to apparatuses and methods to address these and other difficulties.
According to one embodiment there is provided a door strut for a wind load door comprising a mounting portion, the mounting portion including a fastener mechanism adapted to connect the strut to a panel of the door; a first oblique portion, a first edge of the first oblique portion connected with the mounting portion at a first edge of the mounting portion, the first oblique portion extending at a first angle with respect to the mounting portion; a leg portion, a first edge of the leg portion connected with the mounting portion at a second edge of the mounting portion, the leg portion extending at a second angle with respect to the mounting portion; a web portion, a first edge of the web portion connected with a second edge of the leg portion, the web portion extending at a third angle from the leg portion; and a second oblique portion, a first edge of the second oblique portion connected with a second edge of the web portion, the second oblique portion extending at a fourth angle from the web portion.
According to one aspect of the disclosure the web portion is parallel with the mounting portion.
According to another aspect of the disclosure the first angle is between about 45 degrees and about 135 degrees. According to another aspect, the first angle is about 120 degrees.
According to another aspect of the disclosure the second angle and the third angle are about 90 degrees.
According to another aspect of the disclosure the fourth angle is between about 45 degrees and about 135 degrees. According to another aspect the fourth angle is about 120 degrees.
According to another aspect of the disclosure, the strut further comprises one or more ribs, each rib extending along a portion of the mounting portion and the leg portion. According to another aspect the rib is formed by stamping. According to another aspect the rib is attached to surfaces of the strut by a fastener.
According to another aspect of the disclosure the first oblique portion, mounting portion, leg portion, web portion, and second oblique portion are formed from a single sheet of material and wherein the first, second, third, and fourth angles are formed by bending the sheet. According to another aspect, the material is steel.
According to another embodiment of the disclosure there is provided a wind load door comprising, a plurality of door panels, the panels arranged in a door frame to span a doorway; one or more hinges, the hinges connecting adjacent panels; and one or more door struts, each strut connected with a one of the plurality of door panels, the struts comprising a mounting portion, the mounting portion including a fastener mechanism adapted to connect the strut to a panel of the door; a first oblique portion, a first edge of the first oblique portion connected with the mounting portion at a first edge of the mounting portion, the first oblique portion extending at a first angle with respect to the mounting portion; a leg portion, a first edge of the leg portion connected with the mounting portion at a second edge of the mounting portion, the leg portion extending at a second angle with respect to the mounting portion; a web portion, a first edge of the web portion connected with a second edge of the leg portion, the web portion extending at a third angle from the leg portion; and a second oblique portion, a first edge of the second oblique portion connected with a second edge of the web portion, the second oblique portion extending at a fourth angle from the web portion.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Each panel 11 may be formed as a single sheet of metal rolled or stamped to form a so-called pan. Alternatively, panel 11 is formed from an embossed steel skin surrounding a hollow center. The hollow center may be filled with a thermal and/or sound insulating material, such as a polymer foam. Some panels may include windows 14.
As shown in
According to one embodiment, strut 10 is formed by stamping from a rolled steel sheet. According to a preferred embodiment, the sheet is Commercial Steel type B with a thickness of 0.034″ (20 gauge) with a minimum yield strength of from about 30 ksi to about 80 ksi. According to a most preferred embodiment, the sheet has a minimum yield strength of 80 ksi.
Strut 10 has a mounting portion 100. When the strut is installed on panel 11, mounting portion 100 contacts the end stiles 12 and center stiles 16 of the panel. According to one embodiment, holes are provided through mounting portion 100 at locations corresponding to the end and center stiles of the panel. Fasteners, for example, screws or bolts, are inserted through the holes in the mounting portion 100 and into threaded holes in the stiles. According to another embodiment, the mounting portions 100 of struts 10 are welded to end and center stiles of the panel.
Along one edge of mounting portion 100 is first oblique portion 102. The plane of first oblique portion 102 is at an angle, A, with respect to mounting portion 100. According to one embodiment, angle A is between about 45° and 135°. According to a preferred embodiment, angle A is 120°. A crimp 110 may be formed along the free edge of first oblique portion.
Along the edge of mounting portion 100 opposite first oblique portion 102 is leg portion 104. The plane of leg 104 forms angle, B, with mounting portion 100. According to a preferred embodiment, angle B is about 90°.
Along the edge of leg 104 opposite mounting portion 100 is web portion 106. The plane of web portion 106 forms angle, C, with leg 104. According to a preferred embodiment, angles B and C are each 90° and web portion 106 is parallel with mounting portion 100.
Along the edge of web portion 106 opposite leg portion 104 is second oblique portion 108. The plane of second oblique portion 108 forms an angle D with web portion 106. According to one embodiment, angle D is between 45° and 135°. According to a preferred embodiment, angle D is 120°. A crimp or hem 110 may be formed along the free edge of second oblique portion 108.
Alternatively, rib 112 or a gusset 112′ can be a separate component connected with the surfaces of mounting portion 100 and leg portion 104 by fasteners, by welding, or by other connecting techniques known in the art.
Multiple ribs 112 or gussets 112′ are provided along the length of strut 10. According to one embodiment, ribs 112 or gussets 112′ are provided at regular intervals along the length of strut 10. For example, the interval may be every foot, every two feet, or every three feet along the length of strut 10.
Despite being shorter and requiring less material to form that the prior art strut, strut 10 according to the present disclosure is stronger. Sixteen-foot long struts with cross sections shown in
Cut-outs 105 may be formed by a stamping die to create holes in the sheet of material that forms strut 10. Alternatively, such holes may be created by cutting, burning, forging, or other process known in the art. The sheet, including the holes, is then formed into the Z-shaped cross section shown, for example, in
While illustrative embodiments of the disclosure have been described and illustrated above, it should be understood that these are exemplary of the disclosure and are not to be considered as limiting. Additions, deletions, substitutions, and other modifications can be made without departing from the spirit or scope of the disclosure. Accordingly, the disclosure is not to be considered as limited by the foregoing description.
