Fluid handling – Systems – With flow control means for branched passages
Reexamination Certificate
2000-06-26
2001-05-29
Fox, John (Department: 3753)
Fluid handling
Systems
With flow control means for branched passages
C126S0390BA
Reexamination Certificate
active
06237638
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a gas distribution manifold assembly for a gas cooking range.
DESCRIPTION OF THE PRIOR ART
A typical gas range has at least one, and usually several, top burners and may also have an oven burner. A manifold assembly is used to distribute gas from a gas inlet to the burners through valves, including burner valves for the top burners and a thermostatic control valve for the oven burner.
A manifold assembly of a type that was widely used in the past includes a round thick wall tube or pipe having a circular cross section. The wall of the tube or pipe is thick and strong enough to permit components of the assembly to be attached directly to the wall by threaded connections. Thus, an inlet end of the tube or pipe is threaded to mate with a gas supply fitting, and the other end of the tube or pipe is closed, for example by a cap or a plug threaded onto or into the pipe. Burner valves are attached directly to the wall of the tube or pipe, typically by threading a nipple of the valve body into a female threaded hole formed in the wall of the tube or pipe. Because of the configuration of a typical range, the tube or pipe may require at least one bend or elbow along its length.
This type of manifold assembly is heavy and expensive due to its massive wall thickness and the number of parts and assembly operations required for its manufacture. To overcome these disadvantages, the modern trend is to make manifold assemblies using thin wall tubing instead of thick wall pipe or tube. Various approaches have been employed, but none has fully met the need for a manifold assembly that is low in cost and easy to assemble.
One approach is to use a thin wall round tube having a circular cross section throughout its length. One advantage is that a round tube is low in cost. Another advantage is that a round tube can be easily formed with one or more bends using readily available numerically controlled equipment, and the bends can be relatively sharp, with a small radius of curvature. Thin wall round tubing has problems however. Thin wall tubing does not permit the direct attachment of threaded inlet fittings and caps to the ends of the tube because the material is not sufficiently thick and strong. Typically therefore the inlet end of the thin wall tube has a machined inlet fitting welded in place and the opposite end is closed by a welded in place plug or by pinching the tube wall. It is difficult to mount burner and thermostat oven control valves to a tube wall having a circular cross section. Because the tube wall is not thick enough to accept threaded nipples, the valves are attached by a fastener system, and it is difficult to fasten valve bodies to a circular surface. A saddle arrangement or other complex structure and/or difficult assembly operation is required to reliably mount valve bodies to a round thin wall tube.
In an attempt to overcome problems with a tube having a circular cross section, tubes with flat walls have been employed. One known manifold assembly is made with a thin wall tube having a square cross section throughout its length. Another known manifold assembly uses a flattened thin wall tube with opposed curved side walls and opposed flat top and bottom walls through out its length. Flat walls have the advantage that it is easier to mount valves to a flat surface than to the curved surface of a round tube. However the flat wall tubes have other problems. It is difficult to form a bend in a square or flattened tube. Such a tube cannot be shaped into a sharp, small radius bend. In addition, such tubes can only be bent in limited ways. A bend in a plane that is not parallel or perpendicular to the flat tube wall is not practical. Finally, it is difficult to attach an inlet fitting or a cap or plug to the end of a thin wall tube having a non-circular cross section.
U.S. Pat. No. 2,896,975 discloses a pipe manifold using a round pipe with a thick wall section strong enough to receive a threaded valve nipple. At locations where valves are to be attached, the pipe is deformed to reinforce the pipe. The deformed segments include flattened, angled side walls and a flat top wall.
U.S. Pat. No. 5,979,430 discloses a manifold having tube portions of square cross section. The ends of the square tube are deformed outwardly by a mandrel to an enlarged diameter round shape that can accept round plugs to seal the tube ends. In addition, prior to the present invention, Harper-Wyman Company has made and sold Harper 7060 and 7062 Series manifold assemblies using square thin wall tube.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide an improved manifold assembly for a gas range that performs well and is inexpensive to manufacture. Other objects are to provide an improved manifold assembly having a thin wall tube to which valves can be attached without using saddles or the like; to provide an improved manifold assembly having a tube that can be formed with sharp bends in any plane and that can include compound bends; to provide an improved manifold assembly which can accept a simple round inlet fitting; to provide an improved end closure for the tube of a manifold assembly; to provide an improved thin wall tube structure for use in a gas range manifold assembly; to provide an improved method for making a manifold assembly and manifold tube; and to provide a manifold assembly overcoming disadvantages of known manifold assemblies.
In brief, in accordance with the invention there is provided a manifold assembly for a gas range. A thin wall metal tube forms an elongated gas conduit having an inlet end and a closed end. At least one valve is mounted on the conduit for controlling the flow of gas from the conduit. The tube has a first segment along its length, the first segment having a circular cross section with a diameter. The tube has a second segment along its length, the second segment having a non-circular cross section with opposed first and second wall portions alternating with opposed third and fourth wall portions. The first and second wall portions are flat and parallel to one another and are spaced apart by a distance less than the diameter of the first segment. The third and fourth wall portions are spaced apart by a distance larger than the diameter of the first segment. The valve is mounted to the second segment of the tube.
REFERENCES:
patent: 2086125 (1937-07-01), Ewing
patent: 2896975 (1959-07-01), Wahl et al.
patent: 5979430 (1999-11-01), Peed et al.
Catalogue, Harper 7060 and 7062 Series; before Jan. 1, 1999.
Anderson Patrick J.
Asta Joseph L.
Casolari David A.
Fox John
Harper-Wyman Company
Kolehmainen Philip M.
Mason, Kolehmainen Rathburn & Wyss
LandOfFree
Manifold assembly for a gas range does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Manifold assembly for a gas range, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Manifold assembly for a gas range will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2560608