FIELD OF INVENTION

[0001] The presently described invention relates generally to overflow valves as used in plumbing fixtures such as bathtubs, sinks, roof drains and other vessels. More specifically it relates to a new method for the prevention of water overflowing a vessel during an unattended filling operation through the use of a siphonic overflow device that is connected to the conventional drain pipe in place of the existing conventional overflow drain pipe.

BACKGROUND

[0002] Home buyers and new homeowners typically believe that bathtub overflows will prevent their bathtubs from overflowing due to an unattended filling operation. Although this belief is also held by many building inspectors and building code officials, it is incorrect. The Uniform Plumbing Code published by IAPMO does not require bathtub overflows because, as IAPMO recognizes, real bathtub overflows have not existed to date and therefore it would be pointless to require a true overflow.

[0003] The myth of the unattended filling operation bathtub "overflow" started approximately one hundred years ago when manufacturing molds for cast iron bathtubs had a hole for mounting a tub spout inside the tub at the present location of the "overflow". The original purpose for the hole was as a mounting point for the tub filler spout. It was later learned that water from the tub could back siphon through the spout into the water supply. Plumbing codes made this type of installation illegal and the filler spouts were moved up the wall to prevent such a backflow. With the tub spout moved up, manufacturers were left with a hole which had no purpose. The molds for the tubs were expensive and the manufacturers could not afford to change the mold to remove the hole. The first idea was a solid plate mounted in the hole with a chain attached to the plate and a rubber drain stopper at the other end. This idea was used for sometime until a second idea came along, namely the tub stopper and trip lever to move to move the tub stopper up and down. The lever is attached to a rod which went down the backside of the tub and then under the tub to the drain where it attaches to the stopper. This assembly required a housing to enclose the trip lever rod. Once this housing was in place some trip lever plate manufacturers cut a slot in the plate.

[0004] What is thought of as a conventional bathtub "overflow" is actually a slot in the trip lever assembly housing which allows for a relatively small amount of water to flow down the housing when the water level in the tub reaches the level of the trip lever assembly housing and the slot. These slots were dubbed "overflows". These slots do not actually prevent a tub from overflowing during an unattended filling operation, nor was there ever any intention for these slots to be a real overflow. This is reflected in that there was never any code work (standards creation, engineering calculations, testing protocol, or listing) created to make these slots a true overflow.

[0005] One problem with conventional "overflows" is that their name is a misnomer.

Other problems are that manufactures of the wastepipe assemblies do not know in advance the flow rate of water into any specific bathtub and there is no limit set by any plumbing code as to the number of inlets or flow rate requirement for any inlet. Flow rates from these inlets can range from 6 gallons per minute up to 24 gallons per minute or more depending on what type of filler valve is installed and the water system pressure. In many cases a bathtub will overflow even if the drain is left open due to the mismatch in fill flow rate and drain flow rate for any specific bathtub, as installed. Typically the bath tub filling system includes a valve that operates under 50 psi to 80 psi of pressure, a draining system that includes a convention bath tub drain pipe having a diameter of 1 1/2" and that drains by gravity flow and the convention slot type "overflow". As such, the inlet flow rate typically is greater than discharge flow rate of the combined conventional, gravity drain outlet flow rate and the conventional "overflow" flow rate. As such, a bathtub overflow that "protects against accidental flooding resulting from an unattended filling operation" is not known, until the present invention.

[0006] Because of the problems associated with conventional "overflows", there is a need for a true bathtub overflow system and method for effectively protecting against accidental flooding during an unattended filling operation by providing an overflow draining flow rate that is greater than the filling rate for a bathtub.

SUMMARY

[0007] The presently described invention relates generally to overflow plumbing as used in fixtures such as bathtubs, sinks and other vessels. More specifically it relates to a new system and method for the prevention of water overflowing a vessel during an unattended filling operation through the use of a siphonic overflow device that has a flow discharge rate greater than the fill rate for the vessel.

[0008] In the present application, embodiments of the present siphonic overflow drainage system is referred to as the No Overflow Siphonic Overflow ("NOSO"). This system prevents flooding by the intermittent use of siphonic action to lower a water level in a bathtub when the fill rate of water into the tub has caused the water level in the tub to reach a predetermined level, thus preventing overflow from containment vessels, such as, but not limited to, bathtubs, lavatory washbasins, sinks, hot water heater catchment trays and other catchment trays.

[0009] An exemplary set of circumstances and sequence of events that could give rise to the need for and that would initiate the presently describe device are as follows. A bathtub or other vessel is being filled with water through the bathtub inlet. The bathtub drain is closed and the water level begins to rise. The person responsible for filling the bathtub forgets that the tub is filling. When the water level reaches the invert level of the vessel overflow and water begins to discharge over and into the overflow, then the water in the drain pipe, in cooperation with the present siphonic system, creates a siphon and greatly increases the rate of water flowing through the overflow such that the water drainage rale exceeds the water fill rate and flows out the drain. When the siphonic discharge is complete, then normal, lower flow rate drain of overflow water then falls or drains away into the sewage system in the normal manner and without causing any damage.

[0010] In general, when the fill rate of water, or other liquid filling the vessel exceeds the drain rate of the vessel, the water level will rise to the level where the vessel (if open-topped) will overflow. These flow rates may also be expressed in terms of the ratio between the overflow cross-sectional area and the incoming water pressure in relation to or not in not in balance with the capacity of the bathtub (or other vessel) to drain excess water that is flowing into the bathtub or other vessel from the inlet piping.

[0011] Because the NOSO device uses the principle of siphoning, it has the capability to discharge water from a vessel at a flow rate that is greater that the gravity drainage flow rate of conventional drainage or overflow systems. The NOSO device is comprised of: 1) a NOSO cable system and waste water overflow housing designed to operate the tub stopper up and down and to be the inlet for the NOSO device positioned in the conventional place of the trip lever assembly housing and of sufficient size to fully encompass the hole for the conventional trip lever assembly housing ("overflow housing"); 2) an outer pipe of the NOSO device which is of a diameter twice the size of the waste water pipe, which is open at the top toward the inlet of the overflow housing and connects directly to the waste water pipe to thereby create a direct flow from the overflow housing to the waste water pipe in the gap between the outer pipe, middle pipe and inner pipe ("outer chamber overflow"); 3) a middle pipe of the NOSO device which is of a diameter one and a half times the size of the waste water pipe which is open at the top toward the inlet of the overflow housing and closed toward the waste water pipe and functions to create a main chamber for overflow ("main overflow chamber"); 4) an inner pipe of the NOSO device which is of a diameter one-half times the size of the waste water pipe which is open at the top toward the opening for the inlet of the overflow housing and open toward the waste water pipe to create an inner chamber for overflow ("inner overflow chamber"); and 5) an inverted "u" cap position just above the inner pipe, which is the same diameter as the waste water pipe, is closed at the top toward the inlet of the overflow housing, open toward the inner pipe and functions to block the overflow from directly going into the inner pipe.

[0012] The distance between the lop of the inner pipe and the opening in the overflow housing is set to be sufficient, under conventional siphonage principles to create the pressure, or "head", necessary to actuate the siphonic effect in the siphonic chamber.

[0013] The clearance between the inner pipe, the inverted "u" cap and the middle pipe and inverted "u" cap is set to be a distance sufficient to allow for the siphonic effect to occur between middle pipe, inner pipe and the inverted "u" cap when sufficient head is present, thus creating a siphonic chamber ("siphonic chamber").

[0014] When the rising water level reaches Ihe invert level of the NOSO device overflow housing (NOSO inlet) in the vessel, water discharges through the NOSO device overflow housing initially into the outer overflow chamber, draining away to the waste water pipe by gravity flow as normal. As the water inlet valve remains on and the water level continues to rise, water begins to enter the main overflow chamber, filling it such that water begins to be evacuated through the inner overflow chamber. If the inlet water continues to rise and envelopes the full diameter of the NOSO device overflow housing, the column of water in the main overflow chamber rises because the dimensions and positioning of the middle pipe, inner pipe and inverted "u" cap, each to the other, causes a flow restriction. It is this rise in water in the main overflow chamber that creates the imbalance of atmospheric pressure, or "head", necessary to actuate the siphonic effect in the siphonic chamber.

[0015] Creation of the head necessary to activate the siphonic chamber enables and causes the overflow water not evacuated through the outer chamber overflow to be evacuated by the siphonic effect from the main overflow chamber. The water flowing in the main overflow chamber pushes the air in front of it, through the siphonic chamber and through the inner overflow chamber. This water is then evacuated from the inner overflow chamber and finally drains into the conventional waste water pipe. As the siphonic effect is actuated, the water level quickly drops in the bathtub even though the same volume of water enters the bathtub from the bathtub inlet. [0016] The effective overflow area of the NOSO device is determined by taking the product of the diameter of the NOSO device overflow housing and the thickness of the NOSO device overflow housing, then multiplying it by pi, then dividing the resulting number by two.

[0017] An alternative embodiment of the NOSO device includes weep holes in the bottom of the middle pipe, outside of the inverted "u" cap. These weep holes function to permit some of the overflow from the main overflow chamber to flow directly to the outer overflow chamber and to drain any water found at the bottom of the main overflow chamber. The drainage through the weep holes also functions to prevent pooling in the main overflow chamber and to prevent any problems associated with stagnant water that otherwise might remain in the main overflow chamber.

[0018] The above summarized features of the NOSO device are provided in order that the detailed description thereof may be better understood, and in order that the advantages of the present systems may be better appreciated. Additional features and embodiments of the systems will be described hereinafter and will form the inventive subject matter supporting the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the systems are not limited in application to the details of construction or to the arrangements of the components set forth in the following description or illustrated in the drawings. Rather, the systems may be practiced in numerous forms and embodiments, and of being practiced and carried out in various ways, all within the scope of the present inventions. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. [0019] These and other embodiments, features, aspects, and advantages of the inventive systems will become better understood with regard to the following description, appended claims and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The foregoing aspects and the attendant advantages of the present invention will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0021] FIG. 1 is a 3/4 perspective view illustrating a part of a preferred embodiment cable system and waste water overflow housing.

[0022] FIG. 2 is a cut-away side perspective view illustrating the Figure 1 embodiment.

[0023] FIG. 3 is a cut-away front perspective view illustrating the Figure 1 embodiment.

[0024] FIG. 4 is the formula for the NOSO device effective overflow area.

[0025] FIG. 5 is a cut-away perspective view of an alternative embodiment that includes weep holes.

DETAILED DESCRIPTION

[0026] The presently described invention relates generally to overflow system, valves and method used to prevent overflows in plumbing fixtures such as bathtubs, sinks, roof drains and other vessels. More specifically it relates to novel systems, method and devices for the prevention of water overflowing a vessel during an unattended filling operation through the use of a siphonic overflow valve in place of the existing conventional overflow drain pipe.

[0027] Various aspects of specific embodiments are disclosed in the following description and related drawings. Alternate embodiments may be devised without departing from the sprit or the scope of the present disclosure. Additionally, well-known elements of exemplary embodiments will not be described in detail or will be omitted so as not to obscure relevant details. Further, to facilitate an understanding of the description, a discussion of several terms used herein follows.

[0028] The work "exemplary" is used herein to mean "serving as an example, instance or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term "embodiments" is not exhaustive and does not require that all embodiments include the discussed feature, advantage or mode of operation.

[0029] In the present application, the device is designed to prevent flooding by the intermittent use of siphonic action to lower a water level thus preventing overflow over a containment vessel, such as, but not limited to, bathtubs, lavatory washbasins, sinks, hot water heater catchment trays and other catchment trays.

[0030] An exemplary set of circumstances and sequence of events that give rise to the need for and that would initiate the presently describe siphonic device are as follows. A bathtub or other vessel is being filled with water through the bathtub inlet. The bathtub drain is closed and the water level begins to rise. The person responsible for filling the bathtub forgets that the tub is filling. When the water level reaches the invert level of the vessel overflow and water begins to flow over and into the overflow and down the outer chamber (which is radially outward of the inner chamber) and flows into the conventional drain under gravity powered flow rate, at that moment the water fill rate is greater than the drain rate and the water level rises. When the water in the outer chamber completely fills the outer chamber, it then overflows into the main chamber then into the siphonic chamber. The water then rises in the siphonic chamber, and pushes the air in the chamber upward, over the top of the inner drain pipe and below the cap of the inverted "u" cap. Once all of the air under the cap of the inverted "u" cap has been pushed out and down in to the drain an imbalance in air pressure results, thus creating a siphon in the siphonic chamber. When the siphon is created, the air pressure operating on the relative larger cross-sectional area of the surface of the water in the tub is multiplied in the siphon so that water in the siphonic chamber is forced out of the chamber at a pressure greater than air pressure and at a flow rate greater than the gravity flow rate. Thus, with a greatly increased flow rate of water through the siphon, the water drain rate exceeds the water fill rate; the water level in the tub quickly lowers. When the water level lowers to the level where all of the overflow can be drained out through the outer channel, then the siphon is broken, and the water flows or falls away into the sewage system in the normal manner until (i) someone shuts off the fill water, (ii) reduces the fill rate, or (iii) the water level again rises as described above to create a second siphonic effect, and so on until the filling of the tub is stopped.

[0031] If the ratio between the overflow cross-sectional area and the incoming excessive water pressure from the piping is not in balance the bathtub/vessel can overflow from the flow of the water from the inlet piping. In other words, when the flow rate of the filling water is greater than the flow rate of the draining rate or overflow draining rate of the tub, it eventually will overflow and cause flooding. The present device is functions to prevent the overflow of vessels by enabling an overflow or discharge flow rate the is greater than the fill flow rate by providing structures that automatically create a siphon, and thus multiply the out flow rate to be greater than the drain or overflow rate that would result from a gravity based flow through the conventional tub overflow slit.

[0032] The first part of the overflow prevention device is an upper housing positioned in the place of the conventional trip lever assembly housing and of sufficient size to fully encompass the hole for the trip lever assembly housing, shown at inlet 210 in Figure 2.

[0033] Figure 1 illustrates a 3/4 perspective view illustrating a preferred embodiment cable system and waste water overflow housing 100. Figure 1 further illustrates the relative thickness 110 of the overflow housing 100 in relation to the diameter 120 of the overflow housing 100. The control handle 130 operates the cable system to move the tub stopper up and down and manages the waste water overflow system.

[0034] Referring to Figure 2, the second part of the first preferred embodiment overflow device include outer pipe 220 which is of a diameter preferably about 1 and 2/3 greater than the diameter of a conventional 1 and ½ inch waste water pipe, in other words, about 4 inches. Pipe 220 is connected to transition drain pipe 299, which has an inner diameter that is about 1 and 1/3 greater than the diameter of the conventional 1 and ½ inch drain, or about 2 inches. Pipe 220 is open at the top toward the inlet 210 and connects directly to the transitional drain pipe 299 to create an outer chamber overflow 230 annular channel. This channel provides a direct flow path from the inlet 210 to the transition drain pipe 299, and then to the convention drain pipe. This flow path is the annular gap between the outer pipe 220 and middle pipe 240 for the length or height of the middle pipe 240, and thereafter between the outer pipe 220 and the inner pipe 260 for the length or height of the inner pipe 260 and then to the conventional waste water overflow drain 310. [0035] Figures 2 and 3 illustrate the location of the pipes each with respect to each other, such as the outer pipe 220 in relation to the inlet 210, and the location and flow paths of water overflow through the outer chamber overflow 230, through the siphon and then to the drain.

[0036] The third part of the overflow prevention device is a middle pipe 240 which is preferably of a diameter about 3 inches or twice the diameter of the convention drain pipe. Middle pipe 240 is open at the top toward the inlet 210 and is closed toward the transitional drain pipe 299, and in cooperation with the other components, creates and defines the main overflow chamber 250)

[0037] Also shown in Figures 2 and 3 middle pipe 240 is positioned below and in fluid communication with the inlet 210. As shown by the central arrows, water flows into the main overflow chamber 250 directly from the inlet and from water that overflows from the annular gap at 230.

[0038] A fourth integral part of the preferred overflow prevention device is an inner pipe

260 which is of a diameter which is preferably about 1 inch or 2/3 of the diameter of the convention drain pipe. The pipe 260 is open at the top toward the inlet 210 and directs flow to the conventional drain pipe located downstream as shown at 310 in Figure 3. Water flowing at 270 is the water that flows under and when the siphon has been established.

[0039] Figures 2 and 3 also illustrate the location of the inner pipe 260 as positioned below the inlet 210 and centrally located within the other pipes and its top end preferably positioned in the lower part of the chamber 250, with its closed end defining the bottom of the chamber 250. The diameter of the inner pipe 260 as compared to that of the transitional drain pipe 299, the middle pipe 240 and the outer pipe 220 is shown in both Figures 2 and 3. The flow path of overflow water through the inner pipe 270 to the conventional waste water drain located at 310 is also shown.

[0040] Another integral part of the overflow prevention device is an inverted "u" cap 280 that is positioned just above and is open toward the inner pipe 260. The inverted "u" cap 280 preferably has the same diameter as the diameter of the transitional drain pipe 299, preferably about 2 inches. The "u" cap 280 is closed at the top toward the inlet 210, and blocks draining water from flowing directly into the inner pipe 260. In other words, and as shown in Figure 2, water flowing into the inner pipe 260 must flow through a circuitous route, that is, down the chamber 250, around the bottom of the "u" cap 280, up along the top part of the inner pipe 260 to the top of the pipe 260 and then over the top of pipe 260 and then down into the pipe 260. The top of inverted "u" cap 280 is positioned in the device at a height that is below the height of the inlet 210 and is above the inner pipe 260. The circular wall of the "u" cap extends from its closed top downward toward, but does not contact the bottom of the chamber 250, to provide a gap or flow path from the chamber 250 to the top of the inner pipe 260.

[0041] The distance 300 between the top of the inner pipe 260 and the inlet 210 must be sufficient to create of the necessary pressure, or "head" to actuate the siphonic effect in the siphonic chamber 290 when said sufficient water is present.

[0042] The clearance 320 between the bottom of middle pipe 240 and the bottom of the wall of the inverted "u" cap 280, and the clearance, or gap distance 330 between the outer diameter of inner pipe 260 and the inner diameter of the inverted "u" cap 280 must be sufficient to create the siphonic effect between middle pipe 240, inner pipe 260 and the inverted "u" cap 280 when sufficient head is present in the main overflow chamber 250, thus together cooperating to create a siphonic effect in the siphonic chamber 290 when the bathtub overflows.

[0043] During bathtub filling, when the rising water level reaches the invert level of me device overflow housing 100, water flows through the inlet 210, initially flowing into the outer overflow chamber 230 and draining away by gravity flow as normal. As the water continues to flow into the bathtub and the water level continues to rise and exceed the capacity of the chamber 230 to drain normally, then water begins to enter the main overflow chamber 250. The water entering chamber 250 flows down to the bottom of the chamber, then up through the inverted "u" cap and once reaching the closed end of the cap, back down through the inner overflow chamber or pipe 270. As the incoming water flow exceeds the drain rate, the column of water in the main overflow chamber 250 rises. It is this rise in water in the main overflow chamber 250 that creates the pressure, or "head" necessary to actuate the siphonic effect in the siphonic chamber 290. The siphon is created when all of the air in the siphonic chamber has been pushed out of that chamber.

[0044] Creation of the head that activates the siphon in chamber 290 in turn causes the overflow water not evacuated through the outer chamber overflow 230 to flow out of the main overflow chamber 250 by the siphon effect. The in-rushing water in the main overflow chamber

250 pushes the air in front of it and out through the discharge, thus creating a siphonic effect in the siphonic chamber 290. The water and air are discharged through the inner overflow chamber

270 which finally drains into the conventional waste water drainage 310. After the siphonic effect is actuated, the water level quickly drops in the bathtub even though the volume of water entering the bathtub from the bathtub water inlet remains constant. In effect, air pressure on the relatively large surface area accelerates the flow of water through the relatively small cross- sectional area of the inner overflow chamber 270, by multiplying me pressure per square inch on the water flowing through the chamber 270 to increase its flow rate.

[0045] The effective overflow area of the device may be expresses as the product of the diameter of the device overflow housing 120 opening and the length of the device overflow housing 110, multiplying the product by pi, then dividing the resulting number by two, show by the equation of Figure 4. Figure 4 is the formula for calculating the device's effective overflow area.

[0046] Referring to Figure 5 an alternative embodiment includes weep holes 500 in the bottom of the middle pipe 240, radially outward of the inverted "u" cap 280. The holes permit weeping some overflow water from the main overflow chamber 250 into the outer overflow chamber 230. Figure 5 illustrates a cross-section view of the middle pipe 240, inner pipe 260, and inverted "u" caps 280 in relation to the location of the weep holes 500 in the alternative embodiment.

[0047] Although specific embodiments of the overflow prevention device have been described, various modifications, alterations, alternative constructions, and equivalents are also encompassed within the scope of these inventions.

[0048] The specification and figures are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, deletions, and other modifications and changes may be made thereunto without departing from the broader spirit and scope of the inventions as set forth in the claims.