Drying and gas or vapor contact with solids – Apparatus – Rotary drums or receptacles
Reexamination Certificate
2001-11-09
2003-04-22
Lazarus, Ira S. (Department: 3749)
Drying and gas or vapor contact with solids
Apparatus
Rotary drums or receptacles
C034S235000, C220S003200, C220S003300, C137S360000
Reexamination Certificate
active
06550157
ABSTRACT:
FIELD OF THE INVENTION
This invention relates, generally, to a recessed rough-in box for a dryer vent, to vent assemblies for use in combination with dryer vent rough-in boxes and, more particularly, to dryer vent rough-in boxes and vent assemblies which are designed to work effectively in hollow walls framed with 2×4 scantling lumber.
BACKGROUND OF THE INVENTION
In 1833, only a year after the city of Chicago began to rise from the treeless glacial plain adjacent lake Michigan, a carpenter from Connecticut named Augustine Deodat Taylor contracted to build a large number of houses in that Illinois city. Taylor responded by building what had become known as balloon frame houses. The walls, ceilings and roofs of a balloon frame structure are constructed from interconnected scantling frames which are subsequently covered. Though Taylor is frequently credited with the invention of the balloon frame structure, it seems that the construction technique emerged over several decades as a popular hybrid of many diverse building methods. In the historic Mississippi River town of Ste. Genevieve, Mo., the French were constructing houses, which still stand, using building methods which were precursors of the balloon frame method. Typically, the French constructed houses with palisade walls-vertical wooden posts placed side by side on 16-inch centers, with a continuous plate nailed across the top. Apparently, the walls were built flat on the ground, then tilted up within trenches dug along the perimeter of the building. Eventually, this palisade construction was modified so that the posts were nailed onto timber sills resting on stone or brick foundations. When standard-size lumber is substituted for the posts, the process is very close to the balloon construction method.
Light-weight, wood-frame houses have become the standard in this country. Because they are quite resistant to destruction in earthquake-prone regions, they are being adopted in faraway places, such as Japan, where killer earthquakes are common.
One of the distinguishing characteristics of wood-frame buildings is that the walls are generally hollow. The hollow walls facilitate the invisible routing of electrical, telecommunications and security system wiring, as well as gas and water pipes. Structural lumber used for nearly all interior walls, and for some exterior walls is typically 2×4 scantling having a generally rectangular cross section that measures about 3.8 cm by 8.9 cm (1.5 inches by 3.5 inches). The walls are typically covered with gypsum board sheets that are nailed or screwed to the framing material. For residential applications, the gypsum board sheets have a standard thickness of about 1.25 cm (½ inch). For commercial applications, the thickness of the gypsum board is about 1.59 cm (⅝ inch). Thus, the depth of a standard hollow interior wall, as constructed within the United States, is either 10.15 cm (4.0 inches) or 10.5 cm (4⅛ inches).
Within the past twenty years, it has become customary to install the drain and the hot and cold water taps for a washing machine in a recessed box that is coupled to the drain. Not only is space saved for washer installation, but any leaks from the taps flow into the drain. Clothes dryer vent installations have, as a rule, been notoriously sloppy. Not only has it been customary to terminate the vent pipe flush with the back wall, many builders install dryer vent pipes in 2×4 framed walls. As the width of a 2×4 stud is actually 3½ inches, 4-inch aluminum vent pipes are frequently compressed so that they are of oval cross section. The main problem with using a 4-inch vent pipe in a 2×4 framed is that it must pass through the top plate of the wall. It is nearly impossible to neatly compress an aluminum vent pipe so that will pass through the top plate and still leave a portion of the plate on either side of the pipe. A further problem is the frequent necessity of running the vent pipe between floor joists or trusses. If the vent pipe has been compressed to pass through a 2×4 top plate, there are no elbows available that will mate to a compressed 4-inch vent pipe and then, after the 90-degree bend, revert to 4-inch round pipe. These problems result in very sloppy installations of dryer vents in 2×4 framed walls. If an 90-degree elbow is required after the vent passes through a top plate of the same size, the quality of the installation is typically even worse.
Several U.S. patents have been granted for dryer vent assemblies. A first example is U.S. Pat. No. 5,590,477 to Carfagno, which discloses a dryer venting assembly having upper and lower mating rectangular housings, each of which has a protruding cylindrical flange with an opening into the housing to provide for the intake or exhaust of dryer exhaust gases. The Carfagno device appears to have two drawbacks. Firstly, neither of the housings provides a recess into which an accordioned flexible dryer conduit may be stored so that the dryer appliance may be positioned flush with the rear wall. Secondly, as the 90-degree transitions are not smooth, they will act as lint traps and also hamper the use of a vent-duct clean-out snake, which requires smooth transitions at right-angle junctions. A second example is U.S. Pat. No. 5,476,183 to Harpenau, which discloses a rectangular rough-in box for a dryer vent. This box, while providing room for an accordioned flexible dryer conduit, does not adequately address the problems inherent in installing a dryer vent in a 2×4 framed wall.
What is needed is an easily-installable, recessed rough-in box for terminating a clothes dryer vent, that will fit in hollow walls framed with either 2×4 or 2×6 scantling studs. Also needed is a set of vent pipes, for use in combination with the recessed box, that can fit within a 3½ inch wide cavity and pass through a top plate of the same width, without eliminating nearly all of the material in the top plate, make a smooth 90-degree bend to level, and transition to a 4-inch round vent pipe.
SUMMARY OF THE INVENTION
The present invention answers the heretofore expressed needs for an improved dryer vent system. According, a several embodiments of a clothes dryer vent system are provided. The vent system is designed for use in hollow walls that are framed with scantling and covered with sheathing secured to the scantling, and that have a hollow interior space that is uniformly at least about 3½ inches wide. The vent system includes a rough-in box for recessed mounting within such a hollow wall, the rough-in box having a substantially planar rear panel, side panels and nonparallel top and bottom panels. The side, top and bottom panels intersect and are unitary with the rear panel, with each side panel intersecting and unitary with both top and bottom panels. The rough-in box also has a depth no greater than about 4 inches, and a stub connector pipe affixed within said top panel, the stub connector pipe having a lower portion of oval-shaped cross section within the box that is couplable to a flexible dryer vent hose and an upper portion outside the box directly couplable to an oblong vent pipe having a minor cross-sectional dimension no greater than about 2 inches. The top panel of the rough-in box incorporates a stub A vent pipe so dimensioned has a cross sectional area of about 13 square inches, which is ½ square inch more than that of a 4-inch diameter vent pipe. Because the Uniform Building Code requires that vent pipe sections which are hidden in wall spaces be metal, this embodiment employs a metal vent pipe stub which transitions from an oval, designed to couple to a standard 4-inch flexible vent duct, to a 2-inch×7-inch connector. Also included in the vent system is at least one section of oblong vent pipe interconnected between the rough-in box and an exterior vent.
Several embodiments of the improved recessed rough-in box are provided, each of which has the attributes set forth above. The first embodiment thereof is designed for mounting bet
Fox III Angus C.
Lazarus Ira S.
Rinehart K. B.
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