Patent Application
20110314762
1. Technical Field
The invention relates generally to an improved door and method of manufacturing. More particularly, the invention relates to an impact resistant door having an interlayer capable of withstanding flying debris. Specifically, the invention relates to a door with an interlayer having a woven structure disposed within an internal cavity.
2. Background Information
Doors provide homes with the ability to access the interior while providing security and restricting access as necessary. In hurricane prone areas of the world, doors must meet certain requirements in order to meet local safety standards. One of the more difficult standards to meet is the impact resistance requirement for flying debris that could be encountered. One of the common tests for flying debris is the typical large missile test. This test consists of firing a nine pound 2×4 piece of lumber with the end impacting the door at approximately 34 miles-per-hour. Ultimately, the door must prevent the 2×4 from passing through the door and potentially injuring the occupants.
Solid doors provide a great deal of impact resistance but suffer from a number or setbacks. First, solid doors are substantially more expensive than hollow doors because of the shear amount of material necessary. Second, solid doors are substantially heavier and more difficult to transport and mount in a doorway. Third, solid doors manufactured out of wood warp more easily and can require maintenance.
An alternative to solid doors are hollow doors. While hollow doors provide reduced costs and easier transportation and mounting, the hollow doors can be unsafe in areas where flying debris is a risk. Hollow doors generally include a pair of skins, or an inner and outer panel, attached to a central frame. The skins may be manufactured from a metal, wood, or a composite. Metal skins provide the necessary structure and impact resistance, but are generally unsatisfactory to consumers because of the fit and finish of metal. Specifically, metal is difficult to manipulate into a wood-like finish that most consumers desire in a door. Further, metal doors are subject to rusting and denting.
Wood and composite skins provide the desired appearance and finish of a solid door with the weight savings and other benefits of hollow doors. However, the is relative thinness of the skins leaves the home prone to flying debris.
The present invention broadly comprises a door including a frame having a hinge stile, a lock stile, a top rail, and a bottom rail defining an internal cavity, an interlayer secured within the internal cavity, a front skin further defining the internal cavity, and a rear skin opposite the front skin and further defining the internal cavity.
The present invention also broadly comprises a method of manufacturing a door including the steps of securing a hinge stile, a strike stile, a top rail, a bottom rail, and a first skin defining a frame and an internal cavity within the frame, inserting an interlayer within the internal cavity, securing the interlayer within the internal cavity to an inner surface of the frame with a plurality of fasteners, and securing a second skin opposite the first skin and further defining the internal cavity.
The preferred embodiment of the invention, illustrative of the best modes in which Applicant has contemplated applying the principles of the invention, is set forth in the following description and is shown in the drawings.
At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention as claimed is not limited to the disclosed aspects.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.
The impact resistant door of the present invention is indicated generally at 12, as is particularly seen in
Frame 40 is preferably assembled with an adhesive at the joints of the rails and stiles. For example, top rail 20 and bottom rail 22 may include an end joint 46 at each end arranged to receive the hinge stile or lock stile. The hinge and lock stiles are arranged to fit within end joints 46 with adhesive to form frame 40. Stiles 24 and 26 may also include a plurality of grooves 50 running the length of the stiles on both a front side 52 and a rear side 54. Grooves 50 receive adhesive used to mount the front and rear skins to frame 40, and may further receive a plurality of protrusions (not shown) extending from the inner surfaces of the front and rear skins.
In accordance with one of the main features of the present invention, an interlayer 56 is located between front skin 28 and rear skin 30. Interlayer 56 is preferably shaped and sized similar to frame 40 and specifically internal cavity 42. In a preferred embodiment, interlayer 56 is a woven material such as a fiberglass screen cloth, but may also include carbon fiber, Kevlar, or any other suitable material without departing from the spirit and scope of the present invention as claimed. As previously discussed, certain safety standards must be met in order for the doors to be sold in hurricane prone areas. For example, it has been found that an interlayer 56 of woven cloth fiberglass can provide sufficient strength to prevent penetration of a nine pound 2″×4″ piece of lumber impacting the door at 34 miles-per-hour.
Referring to
Having described the structure of a first preferred embodiment, a second preferred embodiment will be described in detail and should be read in light of
Having described the structure of two preferred embodiments, a preferred method of manufacturing will be described in detail and should be read in light of
Initially, rear skin (or front skin if desired) is arranged with outer surface 36 facing down on an assembly table and an adhesive is applied to rear side 54 of top rail 20, bottom rail 22, hinge stile 24, and lock stile 26. Next, top rail 20, bottom rail 22, hinge stile 24, and lock stile 26 are fit together to form frame 40 and internal cavity 42 directly on inner surface 38 of rear skin 30. Interlayer 56 is draped within internal cavity 42 and maybe tensioned and fastened to inner surface 44 of frame 40 with a plurality of fasteners 68. Any excess interlayer is then trimmed away. A second layer of adhesive is applied to front side 52 of frame 40 and inner surface 34 of front skin 28 is secured to frame 40 along the adhesive. Door 12 is placed in a clamp press until the adhesive has cured. After trimming door 12 to its final width and height with a trim saw, the door is placed within a foam press where the door is pre-heated. A liquid foam, such as PUR foam is injected into internal cavity 42 via through hole 70. Plug 80 is inserted into through hole 70 and the foam is permitted to cure, at which point the impact resistant door is considered complete and may proceed through finishing and pre-hanging procedures well known in the art.
Accordingly, the impact resistant door is an effective, safe, inexpensive, and efficient device that achieves all the objectives of the invention, provides for eliminating difficulties encountered with prior art devices, and systems, and solves problems and obtains new results in the art.
In the foregoing description, certain terms have been used for brevity, clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.
Having now described the features, discoveries, and principles of the invention, the manner in which the impact resistant door is constructed and used, the characteristics of the construction, and the advantageous new and useful results obtained; the new and useful structures, devices, elements, arrangement, parts, combinations, and methods are set forth in the appended claims.
