Pipes and tubular conduits – With closures and plugs
Reexamination Certificate
2003-01-29
2003-09-16
Brinson, Patrick (Department: 3752)
Pipes and tubular conduits
With closures and plugs
C138S097000
Reexamination Certificate
active
06619326
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to plumbing repair, and more particularly to a plug for temporarily stemming the passage of water in a pipe while a repair is being carried out.
BACKGROUND OF THE INVENTION
Repair or modification of water system lines typically involves cutting a pipe to remove a portion of the pipe containing a defect and then splicing in a fitting, such as a coupling or joint, over the two exposed ends of the pipe. Typically, water supply and drainage system pipe is constructed of either copper or plastic, such as PVC. When working with copper pipe, brazing, or soldering, is the preferred method for adding in a fitting. Brazing copper pipe usually requires first cleaning and drying the end of the copper pipe and the fitting. Flux may then be applied to the pipe and/or the fitting, which are then assembled. The actual joint is made by heating both the pipe and the fitting and sweating solder into the joint to produce a water tight seal.
Repair of PVC, or other plastic pipe follows a similar scheme. The pipe is first cut to remove the defect, and then a new segment of pipe is spliced in. As with copper pipe, the ends of PVC must first be cleaned and dried. The actual joint is formed using an adhesive between the PVC pipe and the fitting.
Repair of either common variety pipe requires that the pipe and fitting be clean and dry. Even small amounts of water at the joint site may compromise the seal and result in the failure of the joint. Unfortunately, even with the water supply to the pipe shut off, there will often remain a persistent trickle of water through the pipe long after the supply has been shut off. Most often this lack of positive shut off is a result of a faulty valve, or simply the gradual evacuation or draining of water that is contained in the water system upstream of the repair site. The trickle of water often results in a defective joint that will have to be repaired, often under the same circumstances that resulted in the initial defect.
A number of disclosures have been made directed at temporary plugs for use in plumbing applications; many of these disclosures are directed at temporary plugs for blocking sewage pipe systems during initial integrity testing of the system during construction. Most of these disclosures are directed at frangible, rather than purely soluble plugs. For example, U.S. Pat. No. 6,267,001 is directed at a plug for testing a waste water line in which the plug includes a disk of material which remains structurally intact when dry and which loosens its structural integrity when wet. This disk of material is covered with a moisture barrier. It is necessary to mechanically break the plug or to physically rupture the moisture barrier in order to restore flow to the pipe. The disclosed plug is designed to be incorporated into the plumbing system at the time the system is constructed. Therefore, the plug cannot readily be added to the system for making repairs at a later time.
Similarly, U.S. Pat. No. 4,739,799 is also directed at a frangible plug for closing off a sewage line for testing the line for leaks. The disclosed plug is maintained in an annular groove in a sleeve that must be incorporated into the pipe system as it is constructed. The sleeve includes a device that may be operated from the exterior of the sleeve to break the frangible plug. Such a device may be a screw or bolt passing through the sleeve and bearing on an edge of the plug. As with the previous disclosure, the sleeve and the plug must be incorporated into the plumbing system at the time the system is constructed.
U.S. Pat. No. 4,357,960 discloses a plug formed from a mixture of alginate and bentonite. Bentonite is a clay product that swells when wet. Water soluble alginate is used as a binder for the bentonite. The bentonite and alginate may be mixed into a formable state and inserted into an end of a pipe to be repaired, for example by rolling the mixture into a sphere that is slightly larger than the inside diameter of the pipe. Repair of the pipe may then be carried out in the conventional manner. The plug will disintegrate and/or dissolve and will wash down the drain when the water supply to the pipe is turned on.
Similarly, U.S. Pat. No. 5,318,075 discloses a water soluble drip stop plug for stopping water flow in a pipe that is formed from polyethylene oxide which will dissolve after a predetermined time after water flow is restored to the pipe. The disclosed plug is cup-shaped having end and side wall thicknesses selected to provide a predetermined time for repair. Typically, the end wall is designed to dissolve prior to the side wall. The cup-shape of the plug is used because it reduces the volume of material that must be dissolved and purged from the pipe.
SUMMARY OF THE INVENTION
A plug for temporarily restraining the flow of water comprising a fibrous body configured to be received in a pipe, said fibrous body comprising water soluble fibers.
A method of temporarily retraining the flow of water in a pipe comprising providing water soluble fibers wherein said fibers will dissolve in water, providing a pipe where said pipe has a flow of water, shaping said fibers in the form of a plug to temporarily restrain the flow of water in said pipe until said fibers dissolve in said water, and placing said fibers into said pipe to temporarily restrain the flow of water.
A method for manufacturing a plug to temporarily restrict the flow of water in a pipe comprising identifying a flow of water to be restricted and identifying the rate of flow of said water and the temperature of said water and selecting a time for restricting the flow of said water. This is followed by the step of selecting a water soluble fiber for restricting said flow of water for said selected time wherein the water solubility of said fiber is adjusted to provide said selected time as a function of the water solubility of said fiber and the molecular weight of said fiber. This is followed by the step of shaping said fibers in the form of a plug and positioning said plug in said pipe to temporarily restrict the flow of water for said selected time.
REFERENCES:
patent: 3338499 (1967-08-01), Gilbert
patent: 4357960 (1982-11-01), Han
patent: 4739799 (1988-04-01), Carney et al.
patent: 5186214 (1993-02-01), Savard
patent: 5246770 (1993-09-01), Bottiglione et al.
patent: 5318075 (1994-06-01), Roll
patent: 6627001 (2001-07-01), Duncan
American Felt & Filter Company
Brinson Patrick
Grossman Tucker Perreault & Pfleger PLLC
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