The present invention relates generally to movable barriers having transverse stiffeners. More specifically, one or more embodiments of the present invention relate to upwardly acting sectional doors having improved resistance to bowing both during and after production due to transverse stiffeners within the door. More particularly, the present invention relates to sectional door panels having stiffeners extending laterally therein to prevent bowing of the door panel without affecting the exterior appearance of the panel.
Movable barriers, such as garage doors and the like, generally include a multi-panel door supported by a track system, upon which the door is movable between an open, horizontal position and a closed, vertical position. The door panels are pivotally secured to each other via hinges and movably secured to the track system via rollers.
Consumers have steadily indicated a desire for lighter weight, thermally efficient door panels, to reduce energy costs and noise while improving safety. Such door panels may be constructed using a front facer and a rear facer that define a volume therebetween. That volume may be filled with a foamed polymer material or the like. The foam adds structural integrity, adheres the panel components together, and improves the door's insulating properties. Such designs are lighter and in some cases less expensive than traditional solid wood or metal doors.
In some cases these foam filled panels are constructed using both a non-metal front facer and a non-metal rear facer. Such panels may be made in a continuous production process wherein a front facer having opposed longitudinal edges is continuously provided, a metal rail is continuously secured to each longitudinal edge, a foaming material is continuously applied on the front facer between the rails, a rear facer is continuously brought into contact with the rails, and the front facer, metal rails, rear facer and foaming material are drawn through a laminator which includes a plurality of rollers. This continuous production process is an improvement in many respects over the prior method, known as a batch process, in which one panel was formed at a time in a mould. The continuous production method is more efficient, less time consuming, and less expensive.
The production of laminated sectional door panels is complex, however, and results in various stresses in the final product as a result of the lamination processing heat, pressure and tension. As a result of these stresses, sectional door panels can become deformed or “bowed” during or after processing. The tendency to deform either during or after processing is highest when the door panel has one or both of its facers made of plastic. Elevated temperatures and pressures of the insulating foam at the time of lamination can cause the resulting sectional door panel to be unstable at ambient conditions. When the insulating foam cools it can shrink at a higher rate than the outer skins of the panel, causing the panel to deform. In addition, normal environmental thermal cycles in some climates can cause insulated sectional door panels to deform long after they have been produced.
Some sectional door panels are produced from blocks of cut foam rather than by a lamination process. These non-laminated insulated door panels do not experience the same processing conditions as laminated door panels, and therefore are not predisposed to deformation like the laminated panels. Nonetheless, these non-laminated door panels often are equipped with vertical reinforcements, known as stiles, which are used for hinge attachment but also serve to reinforce the panel. Although the stiles help to reinforce the door panels, they also significantly affect the appearance of the door panel because they are exposed to the inside of the door.
Thus, there exists a need in the art for a laminated door panel produced by a continuous lamination process having integral reinforcement to prevent deformation, without altering the appearance of the door panel.
In light of the foregoing, it is a first aspect of the present invention to provide a movable barrier having transverse stiffeners.
It is another aspect of the present invention to provide a panel comprising a front facer having opposed longitudinal edge profiles, rails secured to the longitudinal edge profiles, a rear facer secured to the rails, wherein the front and rear facers and the rails form an inner volume, foam disposed within the inner volume, and at least one stiffener disposed within the inner volume and the foam, the stiffener extending substantially transversely between the opposed rails.
It is still another aspect of the present invention to provide a method of forming a panel comprising continuously providing a front facer having opposed longitudinal edges, the edges each having a rail, continuously positioning stiffeners on the front facer, extending between the rails, continuously applying a foaming material on the front facer and the transverse stiffeners, continuously bringing a rear facer into contact with the rails, and drawing the front facer, the rails, the stiffeners, the foam, and the rear facer through a laminator having a plurality of rollers.
It is yet another aspect of the present invention to provide a door system comprising a frame defining an opening in a building structure and having roller tracks mounted thereto, a door formed of a plurality of panels hinged to one another and movable between a closed position and an open position on the roller tracks, each panel comprising a front facer having opposed longitudinal edge profiles, rails secured to the longitudinal edge profiles, a rear facer secured to the rails, foam disposed within the inner volume, wherein the front and rear facers and the rails form an inner volume, and at least one stiffener disposed within the inner volume and the foam, the stiffener extending substantially transversely between the opposed rails, a counterbalance system mounted to the frame and operatively connected to the door, and roller assemblies mounted to the panels having rollers engaging the roller tracks.
For a complete understanding of the objects, techniques and structure of the invention, reference should be made to the following detailed description and accompanying drawings, wherein:
As noted in the Summary, the present invention is directed to a panel with a transverse stiffener and methods for the manufacture thereof. The description will proceed with a general discussion of a door system in which the panel is used and the method of manufacturing the panel. Then the description will proceed with specific details regarding the stiffener and its advantageous features.
A movable barrier in the form of an upwardly acting sectional door system according to the concepts of the present invention is generally indicated by the numeral 20 in
The opening in which the door 21 is positioned for opening and closing movement in conventional fashion is defined by a frame, generally indicated by the numeral 22. Frame 22 is normally constructed of lumber, in a manner well known to persons skilled in the art, for purposes of reinforcement, attachment to the building structure, and to facilitate the attachments of elements involved in supporting and controlling sectional door 21.
As shown in
While a four panel sectional door 21 is depicted in the drawings, it is to be appreciated that more or less panels may be employed in sectional doors of this type, depending upon the height of the door opening and related considerations. As depicted, the sectional door 21 consists of a top panel 40, an upper middle panel 41, a lower middle panel 42 and a bottom panel 43. Adjacent panels 40-43 are interconnected at their longitudinal edges by hinge assemblies, generally indicated by the numeral 50. Door panel 41 interrelates with the roller tracks 31, 32 by virtue of roller assemblies, generally indicated by the numeral 54. The roller assemblies 54 include rollers 56 which are adapted to engage tracks 31 and 32 in a conventional fashion. The door panels of the present invention will be discussed hereinafter in greater detail by reference to the method of their manufacture, with it being understood that panels 40-43 are identical in most all respects but for their position in sectional door 21.
The continuous production method used to produce the door panels of the present invention may be described generally as having a number of distinct steps or stations. However, the specific aspects of the present invention are directed to the inclusion of a transverse stiffener and how its structural features enhance the overall manufacturing of the door panel and the resulting end product. A first step is a facer forming area where a front facer is formed in a continuous fashion by extruding a sheet of plastic and shaping that sheet into a final form. This front facer is then directed to a rail forming and insertion area where metal rails are continually formed and joined with the front facer. After the metal rails are formed and joined with the front facer, transverse stiffeners are placed onto the facer and between the metal rails. Next, in a laminating area a foaming material is discharged onto the front facer, transverse stiffeners, and rail assembly. Thereafter, according to the present invention, a rear facer is continuously provided to complete the exterior shell of the panel. The assembly is then directed through a laminator to maintain the position of the components, simultaneously allowing the foam to expand and fill the interior volume thereby integrating the transverse stiffeners into the panel. After exiting the laminator, the foam is substantially cured and the panel may be cut to length. In one embodiment, if the panels are used in conjunction with a garage door system, the panels may be provided with appropriate hardware, and assembled with other panels to form the garage door.
An exemplary door panel manufacturing method will now be described with reference to the drawings.
After exiting extruder die 114, the thermoplastic material of the front facer 116 has not yet taken a permanent shape, is still impressionable, and may be directed through an embossing roller assembly 118 to form a desired pattern on the facer. Embossing roller assembly 118 may include at least one upper roller 119 and an opposed, spaced apart lower roller 120. Embossing roller assembly 118 is further provided to propel front facer sheet 116 toward a vacuum former 122 at a predetermined or regulated speed.
Optionally, a temperature compensator 124 may be provided downstream of the embossing roller 118 and prior to vacuum former 122. Temperature compensator 124 may be employed to regulate or adjust the temperature of front facer sheet 116 prior to entry into vacuum former 122.
Front facer sheet 116 may then be drawn through vacuum former 122 to form a variety of raised patterns thereon. When assembled in a door system, front facer 116 of the completed door panel is positioned on the exterior side of the door and thus, decorative patterns or embossments may be desirable. Vacuum former 122 may therefore include a patterned loop or belt 126 that is continually drawn along the top surface of a stationary table with both the belt 126 and the stationary table having holes therein. A cooling system 128 may be associated with vacuum former 122. Vacuum former 122 may also be utilized to begin forming the opposing edges of front facer sheet 116 to facilitate assembly of various other door panel components.
To complete the formation of edge portions, front facer sheet 116 is next drawn through a post forming area 130. Post forming area 130 may include conventional formers 132 and 133 which provide a plurality of spaced apertures or slots, through which the edge portions of front facer sheet 116 are directed through. Each aperture may include a shape that is sequentially more similar to the final desired end profiles 136A and 136B as seen in
Facer sheet 116 is next drawn through a water bath 138 to complete the cooling process and permanently set the shape thereof. Upon exiting water bath 138, facer sheet 116 is no longer impressionable and will thereafter maintain its pattern and end profiles. A puller assembly 139 may be provided to draw facer sheet 116 out of water bath 138.
The completed front facer 116 may now be guided to a rail forming and insertion area 150 (hereinafter rail area 150), shown in
In rail forming area 150, a pair of rails 152A and 152B are formed and joined with front facer 116 at edge portions 136A and 136B. Front facer 116 is first drawn through a rail forming apparatus 154 which is adapted to continuously shape metal strips into a desired cross-sectional profile. Rail forming apparatus 154 includes a left side rail former 156A and a right side rail former 156B. Rail formers 156A and 156B are spaced apart to allow front facer 116 to travel uninhibited therebetween. Each rail former 156 is continuously fed from a separate rail stock roll (not shown). The rail stock is of metal composition and is initially in the form of a flattened strip, wound into a roll. The metal stock is fed through respective rail formers 156A and 156B which shape the metal stock as it travels therethrough. Rail formers 156A, 156B output shaped rails 152A, 152B at a speed substantially matching the speed of front facer 116 as it travels through rail area 150. In the present embodiment each rail former 156A and 156B may include a plurality of rotating wheels 158 positioned sequentially to shape the passing metal stock. Each rail former may be driven through a gear arrangement 160 driven by a motor 161. In one embodiment of the invention, rail forming apparatus 154 shapes left rail 152A and right rail 152B to appear as shown in
After shaping by rail forming apparatus 154, rails 152A and 152B are ready to be joined with front facer 116. Rails 152A and 152B provide structural stability, as well as a sturdy mounting area for brackets, hinges or other hardware. Downstream of rail forming apparatus 154, rails 152A and 152B and front facer 116 are joined by a merging apparatus designated generally by the numeral 164. Merging apparatus 164 generally includes a plurality of guides and rollers that allow rails 152A and 152B to be continuously joined with the edges 136A and 136B of front facer 116. After exiting rail former 156A, left rail 152A is directed through a series of guide blocks 166, 167 and 168, each having a channel corresponding to the shape of left rail 152A. The guide blocks turn and position left rail 152A to the desired position, and the final guide block 168 includes an adhesive applicator which applies adhesive between the left rail 152A and the edge portion 136A. Similarly, right rail 152B is directed through a series of guide blocks 170 and 171 each having a channel corresponding to the shape of right rail 152B. These guide blocks act to turn and position the right rail 152B to the desired position, and include an adhesive applicator to apply adhesive between the right rail 152B and the edge portion 136B. The number of guide blocks for each rail 152 may vary and are not limited to the numbers shown in the Figures.
As shown in
After assembly of front facer 116 with rails 152, the assembly is drawn into a transverse stiffener placement area for placement of transverse stiffeners 180 into the assembly, as shown in
A transverse stiffener 180 of the present invention is shown in
With reference back to
A second embodiment of a transverse stiffener 180′ can be seen in
After placement of transverse stiffeners 180 or 180′, the door assembly, including front facer 116, rails 152A and 152B, and transverse stiffeners, proceeds toward a lamination area generally indicated by numeral 200 as shown in
The joining of the various components can be seen with reference to
Laminator 200 may include a plurality of spaced rollers 212. One or more of the rollers 212 may be rotated in unison by a single or a plurality of roller motors (not shown). In the case of a single motor, the plurality of rollers may be interrelated by belts or chains so that rotation occurs in unison. Further, a belt may be provided below rollers 212 so that the assembled door panel is drawn continuously therebetween. Though the present embodiment discloses a roller and belt type laminator, other suitable types of laminators may be employed. For example, a roller chain conveyor using pressure platens may be used. Such laminators are disclosed in U.S. Pat. No. 5,836,499 which is hereby incorporated by reference. The rollers apply pressure to rear facer 202 as foam material 204 cures, while riding along metal rails 152A and 152B. The rollers may be adjustable to accommodate varying sizes of door panels.
With reference now to
As evidenced by
With reference to
As is readily apparent, there are numerous advantages to the method of inserting transverse stiffeners into a door panel used with a movable barrier and for the door panel itself. Skilled artisans will appreciate that the transverse stiffener disclosed herein is internal to the front and rear facers of a panel. Moreover, the stiffeners are not visible from the inward side of the door and are configured such that the internal foam used to form the panel goes around the transverse stiffener in such a manner so as to integrate it into the finished panel. As a result, external stiles are not required. Moreover, such a configuration contributes to the strength of the panel due to the increased adhesion between the facers and the transverse stiffeners. This is further advantageous in that less galvanizing can be used without concern for oxidation of the stiffeners. In embodiments which use non-metallic facers, use of the transverse stiffeners assist in maintaining their desired planar configuration. In other words, use of the stiffeners as disclosed herein prevents the panels from bowing or otherwise deforming during manufacturing and storage of the panels prior to final manufacturing of a hinged movable barrier. Use of the transverse stiffeners also allows for attachment of hardware in a manner not previously recognized. And all this is done without detracting from the appearance of the final product.
Thus, it can be seen that the objects of the invention have been satisfied by the structure and its method for use presented above. While in accordance with the Patent Statutes, only the best mode and preferred embodiment has been presented and described in detail, it is to be understood that the invention is not limited thereto and thereby. Accordingly, for an appreciation of the true scope and breadth of the invention, reference should be made to the following claims.
This is a divisional application of application Ser. No. 12/151,034 filed May 2, 2008, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | 12151034 | May 2008 | US |
Child | 13008169 | US |