Patent Publication Number: US-2015068142-A1

Title: Arch Drywall Trim Product

Description:
This application is a continuation of application Ser. No. 13/302,092 filed Nov. 22, 2011 which was a continuation of application Ser. No. 12/758,233 filed Apr. 12, 2010 which was a continuation of application Ser. No. 11/707,647 filed Feb. 17, 2007. Application Ser. No. 13/302,092, 12/758,233 and 11/707,647 are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates generally to the field of drywall corner trim and more particularly to an arch drywall trim product that needs no mechanical attachments. 
     2. Description of the Prior Art 
     Drywall corner trim finishing materials available for use on arches are known in the art. The most common are made of vinyl without any surface preparation for bonding to joint compound or other common mastics. 
     Each of the prior art products are designed for a particular installation process which includes nailing, screwing, crimping or otherwise fastening the material to an archway corner. This is sometimes done in conjunction with the use of adhesives. Once the installation is finished, the installer must overlay the assembly with large quantities of drywall mud to cover and hide the fasteners and to blend the assembly into a seamless surface with the flat wall. This is very time consuming and requires that the installer have a drill, screws, or other hardware and equipment in order to perform the installation. It is also very difficult to mechanically attach the trim to the arch, either with screws or otherwise, in a manner such that the arch forms a smooth radius and is free of kinks or steps since the trim material cannot be adjusted after being fastened to the corner. 
     It would be advantageous to have a corner trim arch product with an inside surface designed so that it can be bonded onto the corner with common drywall joint compound or other mastic without any mechanical fasteners. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a notched drywall trim piece that can take the form of a bead, hinged trim piece or bullnose piece that generally is constructed from a semi-rigid core that forms two flanges. At least one of the flanges is notched allowing the piece to follow the shape of an arch or arbitrarily curved corner. The notches allow the otherwise rigid, straight trim piece to be smoothly bent around the corner. 
     The products of the present invention can generally be installed without any mechanical fasteners since the inner or wall-facing surface of the product is prepared or treated to bond directly with drywall mud or other mastic. In this manner, the piece can be installed using only wet mud. The piece can be moved and adjusted in the wet mud and finally finished with a layer of mud on its outer surface. The outer or room-facing surface can optionally be treated or prepared to bond with the mud or can be prepared to directly receive paint or texture. 
     The preparation of the flange surface can take the form of a paper or other fibrous layer, scoring, frocking, roughing, protrusions, or a water-activated adhesive or pressure sensitive (or any other) adhesive may be used. 
    
    
     
       DESCRIPTION OF THE FIGURES Refer to the following images to better understand the present invention: 
         FIG. 1  shows a bead embodiment of the present invention. 
         FIG. 2  shows a trim embodiment of the present invention. 
         FIG. 3  shows a bull-nose embodiment of the present invention. 
     
    
    
     Several illustrations and drawings have been presented to aid in understanding the present invention. The scope of the present invention is not limited to what is shown in the figures. 
     DESCRIPTION OF THE INVENTION 
     The present invention relates to an arch corner trim product with an inside surface designed such that it can be bonded onto a corner with common drywall mud or other mastic without using any mechanical fasteners. What I mean by arch is a trim product that contains a notched flange so that the product can be applied to match the curvature of an arch or other curved drywall corner. The notches allow the otherwise rigid, straight piece of corner trim to be smoothly bent around a curved corner like an arch perfectly matching the curve of the corner. 
     Normally the product includes a semi-rigid core or plastic or other semi-rigid material with a layer of fibrous material like paper on the inside surface so that the product can be better bonded to the corner using only mud. The present invention can be easily adjusted while the mud is wet. It can also be rolled with a roller onto the curved or arched corner to insure a perfect fit and insure that the flanges are tight against the drywall thus using minimum mud and requiring minimum mud to finish out the job. The product of the present invention is very easy to install since the installer does not need to hide screw heads, staples or other fasteners with large amounts of mud. In addition, various embodiments of the present invention include a fibrous or paper layer on the outer surface that has been prepared to directly receive paint or texture. This surface preparation may take the form of impregnation with polymers or paint. 
     The product of the present invention can generally take the shape of any corner trim available as long as the inner surface has been treated, coated, covered or otherwise prepared to bond well with drywall mud or other mastic joint compound. The preparation of the flange surface can take the form of a paper or other fibrous layer, scoring, frocking (bonding a powdered fibrous material), roughing, protrusions, or a water-activated adhesive or pressure sensitive (or any other) adhesive may be used. The preferred method is to use a layer of paper between the semi-rigid core and drywall. This paper can be continuously extruded with the semi-rigid core. A possible form of the product of the present invention can be similar to that disclosed in U.S. Pat. No. 6,148,573 with notches as described above. 
     Turning to  FIG. 1 , a “bead” type embodiment of the present invention can be seen. By bead, I mean a trim product that is manufactured to an approximately fixed flange angle and has a structure along its nose  1  or apex that runs along its length. At least one of the flanges  2  may be notched  5  to allow the piece to bend along the curve of the corner. The nose  1  may optionally also be notched. The wall-facing surface of the flanges  8  is normally treated to bond tightly with mastic preferably by being bonded to a wall-facing paper layer. The outside, or room-facing surfaces  4  of the flanges  2  are also normally treated to directly receive paint or texture. 
       FIG. 2  shows a “trim” type embodiment of the present invention where rather than a bead type nose like the embodiment of  FIG. 1 , the piece has a grooved hinge  6  that allows the piece to flex to any angle. Normally, this embodiment has optionally tapered flanges  2  that are thickest near the nose and taper off toward the edges. Again, at least one of the flanges is normally notched  5  to allow the piece to follow the curvature of an arch corner. 
       FIG. 3  shows a “bullnose” embodiment of the present invention. Here the nose  7  is replaced by a large radius crown which connects the flanges  2  and is commonly known as bullnose in the art. Again, this embodiment is normally notched  5  to allow the piece to follow the curvature of an arch corner. 
     The wall-facing and room-facing surfaces ( 4  and  8  respectively) of the embodiments shown in  FIGS. 2 and 3  are similar to those described for the embodiment shown in  FIG. 1 . 
     As has been previously discussed, the product of the present invention can take the shape of any type of corner trim as long as the inside surface has been treated as described so that it will bond well with drywall mastic. In general, the present invention is manufactured with a rigid core whose inside or wall-facing surface bonds well with drywall mud. The present invention can also take the shape of flat or tapered products currently used in the trade for off-angles (angles different from 90 degrees). These products usually incorporate some sort of hinge along the centerline (such as the embodiment shown in  FIG. 2 ). 
     The surface preparation to make the products of the present invention bond well with drywall mud can take the form of a treatment to the semi-rigid core such as roughening the surface, scoring, protrusions, a fiber coating like paper, or frocking. Any treatment or preparation of the wall-facing surface is within the scope of the present invention. The treatment may optionally also be applied to the outer or room-facing surface, or the room facing surface may include a paper or other layer treated or prepared to directly receive paint or texture. 
     A particular embodiment of the present invention can have the inside and outside of the product treated in the same manner. This can aid in the ability of the product to be bonded to an arched corner only with drywall mud. This is because, in the final installation, the flanges will be captured between an inside and outside layer of mud creating a 2-sided bond. Another embodiment of the present invention can have the wall-facing side of the flanges (or a single flange) pre-treated with a mastic material. This mastic can optionally be an adhesive of any type. A preferred adhesive is one that is water-activated or pressure sensitive. 
     A possible method for manufacturing the arch corner trim products of the present invention is to extrude a semi-rigid core piece such as high impact plastic and then notch one or more of the flanges. The wall-facing surface of the flanges can then be prepared to bond with drywall mud or other mastic. If an adhesive is used, they can be coated with adhesive. It is also possible to continuously extrude the core piece with a layer of fibrous material such as paper that itself can bond with drywall mastic. It is also possible to extrude the core with paper or other surface preparation on the room-facing side that can directly received paint or texture. 
     Several descriptions and illustrations have been provided to better aid in the understanding of the invention. One of skill in the art will realize that numerous variations and changes are possible without departing from the spirit of the invention. Each of these changes and variations is within the scope of the present invention.