Automatic drainage device for radon mitigation systems

A sump cover having a receptacle and an automatic drainage device disposed in the receptacle. The drainage device includes a base platform defining a valve opening in communication with an outlet of the receptacle, a support structure attached to the base platform, a valve stem assembly, and a float assembly. The support structure includes a guide portion defining a slot in alignment with the valve opening. The valve stem assembly is slidingly disposed in the slot and includes a sealing member for selectively closing the valve opening. The valve stem assembly is moveable into a closed position, sealing the valve opening, and moveable into an open position, unsealing the valve opening. The float assembly includes a pin to selectively lock the valve stem assembly in the closed position and releases the valve stem assembly to the open position when a certain amount of liquid is present in the receptacle.

FIELD

The present disclosure relates to sump covers for radon mitigation systems; particularly to sump covers having a drainage device for radon mitigation systems; and more particularly to an automatic drainage device for radon mitigation systems.

BACKGROUND

Radon is a naturally occurring colorless, odorless, and tasteless gas that is also radioactive. Radon has a chemical symbol Rn, atomic number 86, and is produced by the radioactive decay of radium-226. Radon gas is naturally released from rocks, soil, and water. In outdoor environments, radon gas levels are very low and generally not considered harmful. However, radon gas can get into houses or buildings through small cracks or holes in the foundations and can accumulate in the closed structures over time. The United States Environmental Protection Agency (EPA) considers radon gas to be second most frequent cause of lung cancer and recommends mitigation of radon gas in occupied buildings.

Radon enters a house through the lowest level in the house that is in contact with open ground. Typical entry points of radon into houses are cracks in solid foundations, construction joints, cracks in walls, gaps in suspended floors, gaps around service pipes, cavities inside walls, and the water supply. Soil suction systems are commonly used to mitigate radon infiltration into a building. Soil suction systems prevent radon gas from entering the house by drawing a partial vacuum from beneath the house and venting it through one or more pipes to the exterior environment. Soil suction systems typically involve one of four types of soil suction that includes sub-slab suction, drain tile suction, block wall suction, and sump hole suction.

Sump hole suction systems are common for houses with a basement having a sump pit since the sump pit is one of the main vectors for radon gas entering the house. The sump pit is hermitically sealed from the immediate ambient air surrounding the sump pit with a lid, also referred to as a sump cover. An opening is provided in the sump cover, a rubber seal is fitted into the opening, and a suction pipe in inserted through the seal to create a suction point. A mechanical device, such as a fan, is used to extract air from the sump pit through the suction point. The extracted air is exhausted to the external environment. This is done in order to extract radon gas from the soil beneath the house to minimize the radon gas entering the house. An advantage of extracting air from the sump pit is that the sump pit is in fluid communication with the existing drainage system beneath the basement floor and drainage tiles surrounding the house. This connection of drainage system and tiles provides a pressure field extension that enables the extraction of radon gas from the entire footprint of the house.

To ensure the maximum efficiency of radon gas removal from beneath the house, the sump cover is hermetically sealed to prevent internal air from the house from leaking into the sump pit. In older houses, this would include hermetically sealing of all open floor drains leading to the sump pit. A draw back from sealing the sump cover and internal floor drains is that of undesired liquids accumulation within the basement of the house. Such liquids may be the result of unfortunate events such as ground water infiltration into the basement due to a failed sump pump, a break in the house water line, or gray water backup from a sewer line.

Thus, while sump hole suction radon mitigation systems achieve their intended purpose, there is a need for an automatic drainage device that is easily installable to mitigate potential liquid accumulation surrounding the sump cover.

SUMMARY

According to several aspects, an automatic drainage device is disclosed. The automatic drainage device includes a base platform defining a valve opening, a support structure attached to a first surface of the base platform and includes a guide portion defining an aperture axially aligned with the valve opening, an elongated member slidingly inserted through the aperture and supported by the guide portion such that the elongated member is axially aligned with the valve opening, a pivot body having a locking pin insertable into a pin bore of the elongated member to lock the elongated member in a closed position, and a floatable body attached to the pivot body. A sealing member is attached to the first end of the elongated member. A handle is attached to the second end of the elongated member. The elongated member is moveably guided by the aperture to an open position such that the sealing member is spaced from the valve opening and to the closed position such that the sealing member is sealing the valve opening. The pin bore is defined between the first end and the second end of the elongated body. The pivot body is pivotable in a first pivot direction to retract the locking pin out of the pin bore thereby releasing the elongated member to the open position. The floatable body is operable to pivot the pivot body in the first pivot direction in response to a liquid acting on the floatable body, thereby releasing the elongated member to the open position.

In an additional aspect of the present disclosure, the aperture is a slot opening and the pivot body includes a block portion and a pair of parallel arms extending from the block portion. The pair of parallel arms are pivotally attached to the support structure on either side of the slot opening.

In another aspect of the present disclosure, the automatic drainage device further includes a connecting rod having a first distal end and a second distal end spaced from the first distal end. The first distal end is connected to the pivot body and the second distal end is attached to the floatable body. The first distal end of the connecting rod extends through the pivot body and functions as the locking pin.

In another aspect of the present disclosure, the base platform includes a connector portion extending from the second surface and surrounding the valve opening, and a valve seat is defined on the second surface between the valve opening and the connector portion. The sealing member is engageable with the valve seat to hermitically seal the valve opening.

In another aspect of the present disclosure, the sealing member includes a disk-shaped body having an annular mating surface engageable with the valve seat, and a raised portion extending from the disk-shaped body. The raised portion includes a beveled surface facing the valve opening. The sealing member is connected to the first end of the elongated member in such a way that disk-shape body is capable of a wobbly movement with respect to the elongated member.

In another aspect of the present disclosure, the connector portion includes an external surface defining a form factor complementary to a shape of an outlet and sized to provide an interference fit with the outlet to provide a hermetic seal.

In another aspect of the present disclosure, the automatic drainage device further includes a sump cover defining a receptacle including an outlet having a predetermined shape. The connector portion includes an external surface defining a form factor complementary to the predetermined shape of the outlet and sized to provide an interference fit with the receptacle to provide a hermetic seal. The sump cover further defines a channel extending from a peripheral surface of the sump cover to the receptacle.

According to several aspects, an automatic drainage cover is disclosed. The automatic drainage cover includes a sump cover defining a receptacle having an inlet, an outlet, and an interior surface defining a chamber containing a drainage device. The drainage device includes a base platform defining a valve opening in communication with the outlet of the receptacle and includes a valve seat surrounding the valve opening; a support structure attached to the base platform in which the support structure includes a guide portion defining an aperture aligned with the valve opening; a valve stem assembly slidingly disposed in the aperture and includes a sealing member engageable to the valve seat to close the valve opening and a pin bore, in which the valve stem assembly is moveable into a closed position such that the sealing member is engaged to the valve seat and moveable into an open position such that the sealing member is spaced from the valve seat; and a float assembly having a locking pin insertable into the pin bore of the valve stem assembly to selectively retain the valve stem assembly in the closed position.

In an additional aspect of the present disclosure, the valve stem assembly further includes an elongated member having a first end attached to the sealing member and a second end opposite the first end. The pin bore is defined between the first end and the second end. A handle is attached to the second end of the elongated member. The elongated member is axially aligned with the valve opening. The valve stem assembly is moveable into the open position under an urging of gravity.

In another aspect of the present disclosure, the float assembly includes a pivot body pivotally attached to the support structure, a floatable body spaced from the pivot body, and a connecting rod connecting the pivot body to the floatable body.

In another aspect of the present disclosure, the aperture is a slot opening and the pivot body includes block portion and a pair of parallel arms extending from the block portion. The pair of parallel arms are pivotally attached to the support structure on either side of the slot opening. The connecting rod includes a first distal end extending through the block portion defining the locking pin.

In another aspect of the present disclosure, the floatable body is liftable by a liquid, thereby causing the connecting rod to pivot the pivot body in a first pivot direction to disengage the locking pin from the pin bore of the elongated member.

In another aspect of the present disclosure, the base platform includes a bottom surface facing away from the support structure, a connector portion extending from the bottom surface and surrounding the valve opening, and the valve seat is defined on the bottom surface between the valve opening and the connector portion. The sealing member is engageable with the valve seat to hermitically seal the valve opening.

According to several aspects, a drainage device is disclosed. The drainage device includes a base platform, a disk-shaped plug, a flat rectangular bar, a spider frame, a pivot body, floatable body, and a connecting rod. The base platform includes a top surface, a bottom surface, and a valve opening. The bottom surface includes a connector portion surrounding the valve opening and a valve seat between the connector portion and the valve opening. The disk-shaped plug is engageable to the valve seat to hermetically seal the valve opening. The flat rectangular bar includes a first end attached to the disk-shaped plug, a second end having a handle, and a pin bore defined between the first end and the second end. The spider frame is attached to the top surface of the base platform. The spider frame includes a guide portion defining a slot opening axially aligned with the valve opening. The flat rectangular bar is slidably inserted through the slot opening. The flat rectangular bar is moveable to a closed position such that the disk-shaped plug is engaged to the valve seat and moveable to an open position away from the bottom surface such that the disk-shaped plug is spaced from the valve seat. The pivot body includes a block portion and a pair of arms extending from the block portion. The pair of arms are pivotally attached to the spider frame on either side of the slot opening. The connecting rod includes a first distal end and a second distal end opposite the first distal end. The first distal end is inserted through the block portion of the pivot body to define a locking pin insertable into the pin bore to lock the flat rectangular bar in the closed position. The floatable body is attached to the second distal end of the connecting rod. The floatable body is liftable by a liquid, thereby pivoting the pivot body to retract the locking pin from the pin bore to release the flat rectangular bar into the open position.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. The illustrated embodiments are disclosed with reference to the drawings, wherein like numerals indicate corresponding parts throughout the several drawings. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of the particular features. The specific structural and functional details disclosed are not intended to be interpreted as limiting, but as a representative basis for teaching one skilled in the art as to how to practice the disclosed concepts.

FIG.1shows a sump cover10having an automatic drainage device100. The sump cover10is configured to seal an opening12of a sump pit14. The sump cover10and sump pit14are part of a sump hole suction radon mitigation system configured to extract radon gas from the soil beneath a building. A gasket (not shown) is disposed between the mating surfaces of the sump cover10and the building floor16to provide a hermetic seal between the sump pit14and the ambient air surrounding the sump cover10.

A suction pipe18is inserted through the sump cover10to provide a suction point for a mechanical device such as a fan (not shown) to extract air containing radon gas from the soil beneath the building floor16via the sump pit14, thus creating a low-pressure space (Psump) in the sump pit14with respect to the ambient air pressure (Patm) surrounding the exterior of the sump cover10. Ambient air pressure (Patm), also referred to as atmospheric pressure, is typically about 14.7 Pounds Per Square Inch Absolute (PSIA) at sea level. Typical sump hole suction radon mitigation systems operate at a negative pressure differential of 0.5 to 2 inches of water with respect to atmospheric pressure. The air within the sump pit14together with any radon gas extracted from the sump pit14is vented to the ambient atmosphere outside of the building.

The automatic drainage device100is disposed within a receptacle102defined in the sump cover10. The sump cover10includes a channel20extending from a peripheral surface22of the sump cover10to the receptacle102. The channel20directs any standing liquid on the building floor16immediately adjacent the sump cover10to the receptacle102. The automatic drainage device100is configured to automatically open a valve to allow for fluid communication between the sump pit14and the ambient air surrounding the sump cover10when a certain amount of liquid is present in the receptacle102, thus enabling the liquid to drain into the sump pit14.

FIG.2shows a cutaway perspective view of the receptacle102containing the automatic drainage device100ofFIG.1.FIG.3shows a cutaway perspective view of the automatic drainage device100within the receptacle102. For brevity, the automatic drainage device100is also referred to as the drainage device100or device100. Referring to bothFIGS.2and3, the receptacle102includes an interior surface104defining a chamber106for receiving a fluid such as a liquid. The receptacle102includes an inlet108for conveying the liquid into the chamber106and an outlet119connected to the drainage device100for releasing the liquid out of the chamber106. In a non-limiting example, the inlet108is located in an upper portion112of the receptacle102and the outlet119is located in a lower portion114of the receptacle102. The terms “upper” and “lower” are used with respect to the general direction of gravity (g).

The receptacle102may be part of the sump cover10as described above or a freestanding receptacle102. In one embodiment, the receptacle102is integrally formed in the sump cover10by manufacturing methods such as injection molding or vacuum forming of a polymer plastic. In another embodiment, an opening may be created through the sump cover10and a freestanding receptacle102may be inserted through the opening such that the inlet108is positioned on the exterior surface24of the sump cover10and the outlet119is positioned on the interior surface26of the sump cover10facing the sump pit14. The freestanding receptacle102may be manufactured of a metallic material by casting, stamping, folding, assembling and joining of multiple work pieces, and other known manufacturing techniques. The freestanding receptacle102may also be manufactured of a plastic or composite material by injection molding, vacuum forming, additive manufacturing such as 3-D printing, and other known manufacturing techniques.

FIG.4andFIG.5show a cutaway perspective view and a cutaway side view of the automatic drainage device100in a closed state, respectively.FIG.6andFIG.7show a cutaway perspective view and a cutaway side view of the automatic drainage device100in an open state, respectively. The open state means a valve opening105of the drainage device100is unsealed, or open, to allow a liquid to pass through. The closed state means the valve opening105is sealed, or closed.

Referring toFIGS.4through7, the drainage device100includes a base platform103defining the valve opening105, a support structure107mounted onto the base platform103, a valve stem assembly116slidingly connected to and guided by the support structure107, and a float assembly118operable to selectively retain the valve stem assembly116in a closed position and release the valve stem assembly116into an open position based on a level of liquid (H) contained in the receptacle102. For clarity of illustration and description, the floatable body170and the receptacle102are not shown inFIGS.4and6.

The valve stem assembly116includes an elongated member132having a sealing member146, such as a plug146, on one end134for sealing the valve opening105and a handle152on the opposite end136. The valve stem assembly116in the closed position means the valve stem assembly116is in a position such that valve opening105is sealed by the sealing member146. The valve stem assembly116in the open position means the valve stem assembly116is in a position such that the sealing member146is spaced from the valve opening105thus unsealing the valve opening105.

The valve stem assembly116is retained, also referred to as locked, in the closed position to seal the valve opening105during normal operating conditions of the radon mitigation system, during which (Psump) is less than (Patm), and remains in the closed position in the absence of a predetermined amount of liquid in the receptacle102. When a predetermined amount of liquid is present in the receptacle102, the float assembly118releases, also referred to as unlocks, the valve stem assembly116and allows the valve stem assembly116to slidingly move under its own weight to the open position to unseal the valve opening105to facilitate drainage of the liquid from the receptacle102.

Best shown inFIG.6, the base platform103includes a first or top surface109, a second or bottom surface111opposite the top surface109, and a connector portion113extending from the bottom surface111and surrounding the valve opening105. An annular valve seat115is defined on the bottom surface111between the valve opening105and an interior surface117of the connector portion113. As a non-limiting example, the connector portion113includes an exterior surface121defining a substantially cylindrical form factor capable of being inserted into a receptacle102having a circular outlet119or a drainage pipe having a circular cross-section. Best shown inFIGS.5and7, the base platform103is assembled to the receptacle102by inserting the connector portion113through the outlet119of the receptacle102. The exterior surface121of the connector portion113defines a form factor complementary to the shape of the outlet119and sized to provide an interference fit with the receptacle102to provide a hermetic seal. Once assembled, the valve opening105is in fluid communication with the outlet of the receptacle102when the valve stem assembly116is in the open position as shown inFIGS.6and7.

Best shown inFIG.4, the support structure107is mounted onto the top surface109of the base platform103. The support structure107may be that of a spider frame107having a plurality of legs131. At least one or more legs131include a foot133mounted to the base platform103with fasteners135such as pins, screws, bolts, studs, and/or nuts. The foot133may also be welded or chemically bonded to the top surface109of the base platform103. The support structure107includes a guide portion120defining an aperture124that is axially aligned with the center of the valve opening105along an axis A. The aperture124is a through-hole having a shape of a cross-section of the elongated member132.

Best shown inFIG.6, the elongated member132includes a first end134, also referred to as a lower end134, and a second end136, also referred to as an upper end136, opposite the first end134. A pin bore128is defined in the elongated member132between lower end134and the upper end136. The pin bore128is configured to receive a locking pin150to lock the valve stem assembly116in the closed position. The elongated member132is slidingly disposed in the aperture124. The aperture124is sized to cooperate with the elongated member132to support the elongated member132in axial alignment with the valve opening105and allows for the elongated member132to freely move in a first direction138, shown as a downward direction138, and in a second direction140opposite the first direction138, shown as an upward direction140.

In the non-limiting example shown, the elongated member132is a flat rectangular bar132and the aperture124is a slot opening124, having a rectangular shaped through-hole, sized to slidingly support the flat rectangular bar132in alignment with the valve opening105. The elongated member132, or flat rectangular bar132, is slidably disposed within the aperture124, or slot opening124. The guide portion120supports the elongated member132in axial alignment with the valve opening105. Moving the elongated member132in the first direction138places the valve stem assembly116into the open position in which the first end134of the elongated member132is extended through the valve opening105away from the base platform103. Moving the elongated member132in the second direction140places the valve stem assembly116into the closed position in which the first end134of the elongated member132is retracted back through the valve opening105toward the support structure107.

Referring back toFIG.4, a handle152is connected to the second end136of the elongated member132to manually move the elongated member132in the second direction140. A sealing member146such as a disk-shaped plug146is attached to the lower end134of the moveable elongated member132. The lower end134of the elongated member132defines an attachment pin hole172. A pin174is inserted through the attachment pin hole172to attach the plug146to the elongated member132. The diameter of the attachment pin hole172is larger than the diameter of the pin174to allow for a sinusoidal type of movement, also known as a wobbly movement, of the plug146about the lower end134of the elongated member132.

Best shown inFIG.7, the plug146includes a disk-shaped body having an annular mating surface149operable to cooperate with the annular valve seat115to provide a hermetic seal. The plug146includes a raised portion147having a beveled surface151facing the valve opening105. In response to the elongated member132being moved in the second direction140to place the valve stem assembly116in the closed position, the beveled surface151cooperates with the wobbly movement of the plug146to facilitate the guiding and seating of the plug146in such a way that the annular mating surface149is engaged to the annular valve seat115to close the valve opening105.

The float assembly118includes a floatable body170, a pivot body154spaced from the floatable body170, and a connecting rod156connecting the floatable body170to the pivot body154. The pivot body154is pivotally attached to the support structure107. The floatable body170includes a density that is less than the density of the liquid that is intended to activate the drainage device100. For example, for the drainage of a liquid such as water, the density of the floatable body170is preferably less than 0.9 g/cm3at room temperature. The floatable body170may be formed of a hollow blow-molded plastic shell, a low-density closed cell foam, a natural cork material, and other materials having a density less than the density of the activating liquid.

Best shown inFIG.6, the pivot body154includes a U-shaped portion182having a pair of arms184extending from a block portion186. The pair of arms184are pivotally attached to the support structure107on either side of the slot opening124. A benefit of this arrangement of the pivot body154is that the valve stem assembly116will remain locked in the closed position even under a vacuum acting on the sealing plug146when the locking pin150is inserted in the pin bore128.

The block portion186of the pivot body154defines a through-hole160to receive the connecting rod156. A first distal end177of the connecting rod156is inserted through the through-hole160and extends from the block portion186to function as the locking pin150, which is receivable in the pin bore128of the elongated member132. A second distal end176of the connecting rod156is attached to the floatable body170. The pivot body154is pivotable in a first pivot direction164(unlocking), which is shown as a counter-clockwise direction164inFIG.7, and an opposite second pivot direction166, which is shown as clockwise direction166(locking) inFIG.5based on the position of the floatable body170.

The block portion186of the pivot body154and connecting rod156may be formed of a material sufficiently heavy such that the pivot body154naturally pivots in the second (closing) pivot direction166in the absence of a force urging the pivot body154to pivot in the opposite first (opening) pivot direction164. Example of such material may include a high-density plastic, metal alloys, or composite materials.

Referring toFIGS.4and5, during normal operating conditions of the radon mitigation systems and the chamber106is substantially free of liquid, the valve stem assembly116is locked in the closed position by the locking pin150received in the pin bore128of the elongated member132. Referring toFIGS.6and7, the floatable body170is lifted by the liquid in responds to a certain amount of liquid accumulating in the chamber106above a predetermined height (H). The lifting of the floatable body170causes the connecting rod156to rotate the pivot body154in the first pivot direction164, which in turn retracts the locking pin150from the pin bore128. The retracting of the locking pin150releases the elongated member132in the first direction138under the urging of gravity, thus moving the plug146in an outward direction away from the valve seat115to allow for the liquid to drain out of the valve opening105. The drainage device100may be reset to the closed position by pulling the handle152to move the elongated member132in the second direction140so that the locking pin150is reinserted into the pin bore128, thus locking the valve stem assembly116in the closed position.

A main benefit of the device100is that it mechanically locks the valve stem assembly116in a closed position without concern for the pressure differential between P(atm) and P(sump). Another benefit of the device100is that it automatically unlocks the valve stem assembly116to allow for drainage once a certain amount of liquid has been accumulated in the receptacle102. Yet another benefit of the device100is that it is easily resettable by a simple pull of the handle without having to remove the device100from the sump cover10or drain pipe. Still yet another benefit of the device100is the adaptability to connect to various receptacle outlets by modifying the form factor of the connector portion113. Still yet another benefit of the device100is the scalability of the device100for various applications such as hermetically sealing a floor drain in the absent of a liquid and unsealing the floor drain when a level of liquid is sufficient to unlock the valve stem assembly116. Still yet another benefit is that the device100may function as a back flow preventor to prevent the backflow of a pressurized liquid or gas from the sump pit14or floor drain when the device100is locked in the closed position.

While example embodiments have been presented in the foregoing detailed description, it should be appreciated that variations of these embodiments can exist without departing from the spirit and scope of the invention. The embodiments described herein are not intended to limit the scope, applicability, or configuration of the invention. Rather, the detailed description provides sufficient detail to enable one skilled in the art to make and use the invention. Those skilled in the art will perceive applications, improvements, changes, and modifications to the invention. Such applications, improvements, changes, and modifications within the skill of the art are intended to be covered by the appended claims.