Not Applicable
Not Applicable
This invention relates to the field of chimney caps, and more particularly to a one-piece, molded plastic chimney cap.
Chimney caps are known in the art, and have taken a variety of configurations in the past. Typically, they are made of a number of parts fastened together with rivets or screws. This construction has drawbacks in that the several parts must be stamped or otherwise formed, each piece with separate tooling. Then the pieces are assembled together with fasteners, which is a labor-intensive process. The parts are typically stainless steel, galvanized steel, or copper. The galvanized steel and copper parts are subject to eventual corrosion and failure. Fasteners can also corrode, causing the cap to fall apart. The vented side walls of the cap are typically wire screen. The screen can be damaged or loosened by corrosion or by wind-blown debris, thereby admitting vermin or birds into the house.
Accordingly, there is a need to provide a chimney cap that is made of a one-piece construction, thereby eliminating fasteners and assembly.
There is a further need to provide a chimney cap of the type described and that is not subject to rust, corrosion, or deterioration.
There is a yet further need to provide a chimney cap of the type described and that cannot admit vermin or birds into the house.
There is a still further need to provide a chimney cap of the type described and that is of rugged construction for long service life.
There is another need to provide a chimney cap of the type described and that can be manufactured cost-effectively in large numbers of high quality.
In accordance with the present invention, there is provided a chimney cap for use in connection with a chimney flue. The flue has an outside surface and a top edge. The flue exhausts combustion gases from a furnace inside a building. The chimney cap comprises at least one wall. The wall extends between opposite upper and lower edges, and it extends continuously around a closed circuit. The wall has opposite exterior and interior surfaces, with the interior surface defining an interior space. The wall also has a plurality of vent holes through it, which communicate with the interior space to vent the combustion gases.
A roof is attached to the upper edge of the wall. The roof has opposite exterior and interior surfaces. A flange is located adjacent the lower edge of the wall and spaced outside the wall a predetermined distance. The flange has a perimeter extending completely around the wall, and a predetermined thickness. The flange has an interior surface for overlapping engagement with the flue outside surface. A shoulder connects the flange with the lower edge of the wall. The shoulder extends completely around the wall. The shoulder has an interior surface that rests upon the flue top edge. The wall, roof, flange, and shoulder are of one-piece construction. Fastening means are provided for fastening the chimney cap to the flue.
The wall, roof, flange, and shoulder of the chimney cap are molded from a polymeric resin selected from the group consisting of thermoset resins and thermoplastic resins.
A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawing, in which:
Referring now to the drawing, and especially to
A flange 38 is located adjacent the lower edge 22 of the wall 18 and is spaced outside the wall 18 a predetermined distance D. That distance is sufficient to support the chimney cap 10 upon the flue top edge 16, and ranges from about 0.5 inch (13 mm) to about 2 inches (50 mm). The flange 38 has a perimeter 40 extending completely around the wall 18. The flange 38 has a predetermined thickness T1. The flange 38 has an interior surface 42 for overlapping engagement with the flue outside surface 14.
A shoulder 44 connects the flange 38 with the lower edge 22 of the wall 18, and extends completely around the wall 18. The shoulder 44 has an interior surface 46 for resting upon the flue top edge 16. The wall 18, roof 32, flange 38, and shoulder 44 are of one-piece construction with a thickness typically ranging from about 0.12 inch (3 mm) to 0.37 inch (9 mm). The wall 18, roof 32, flange 38, and shoulder 44 are molded from a polymeric resin which can be either a thermoset resin or a thermoplastic resin. The wall interior surface 26 and the roof interior surface 36 can be coated with a metallized coating for heat resistance.
Fastening means are provided for fastening the chimney cap 10 to the flue 12. Specifically, the fastening means comprises a plurality of reinforced regions 48 integral with the flange 38. The reinforced regions 48 are spaced apart around the flange perimeter. Each reinforced region 48 has a thickness T2 greater than the flange predetermined thickness Ti. Each reinforced region 48 has at least one threaded hole 50 through it. In the case of a rectangular wall circuit, the reinforced regions 48 are located at each corner, as shown in
Turning now to
A flange 138 is located adjacent the lower edge 122 of the wall 118 and is spaced outside the wall 118 a predetermined distance. The flange 138 has a perimeter 140 extending completely around the wall 118. Reinforced regions 148 are spaced apart around the flange perimeter. Each reinforced region 148 has at least one threaded hole 150 through it. The flange 138 has a predetermined thickness.
A shoulder 144 connects the flange 138 with the lower edge 122 of the wall 118, and extends completely around the wall 118. The wall 118, roof 132, flange 138, and shoulder 144 are of one-piece construction. Fastening means are provided for fastening the chimney cap 110 to the flue 12.
A capping method is also disclosed for capping a chimney flue 12. The method comprises the steps of extending at least one wall 18 of a chimney cap 10 between opposite upper 20 and lower 22 edges, extending the wall continuously around a closed circuit, and extending the wall 18 between opposite exterior 24 and interior 26 surfaces, then defining an interior space 28 with the interior surface 26. Next, penetrating the wall 18 with a plurality of vent holes 30, and communicating the vent holes 30 with the interior space 28. Next, attaching a roof 32 to the upper edge 20 of the wall 18, and extending the roof 32 between opposite exterior 34 and interior 36 surfaces. Next, providing a flange 38 adjacent the lower edge 22 of the wall 18, spacing the flange 38 outside the wall 18 a predetermined distance D, and extending the flange 38 completely around the wall 18, then connecting the flange 38 and the lower edge 22 of the wall 18 with a shoulder 44, and extending the shoulder 44 completely around the wall 18. Next, constructing the wall 18, roof 32, flange 38, and shoulder 44 of one-piece. Next, overlapping the flue outside surface 14 with an interior surface 42 of the flange 38, resting an interior surface 46 of the shoulder 44 upon the flue top edge 16, and fastening the chimney cap 10 to the flue 12, then venting the combustion gases through the vent holes 30.
Another step comprises molding the wall 18, roof 32, flange 38, and shoulder 44 from a polymeric resin selected from the group consisting of thermoset resins and thermoplastic resins.
Yet another step comprises applying a metallized coating to the wall interior surface 26 and the roof interior surface 36 for heat resistance.
Further steps comprise forming a plurality of reinforced regions 48 integral with the flange 38, providing each reinforced region 48 with a thickness T2 greater than a flange predetermined thickness TI, then spacing the reinforced regions 48 apart around a flange perimeter 40. Next, forming at least one threaded hole 50 through each reinforced region 48, and engaging each one of the threaded holes 50 with a screw 52, then tightening the screws 52, thereby fastening the chimney cap 10 to the flue 12.
A yet further step includes extending the wall 18 continuously around a rectangular closed circuit. An alternative step includes extending the wall 18 continuously around a circular closed circuit.
Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications that will come within the scope of the appended claims is reserved.