Drain apparatus with liquid trap

Claim 1

Apparatus for draining liquid from a surface into a sewer through a passageway extending between said surface and said sewer and for forming a liquid barrier between said sewer and said surface for preventing the flow of gases from said sewer to said surface, said apparatus being selectively, positionable in said passageway and removable therefrom as a unit, and said apparatus comprising, in combination: a conduit including a peripheral wall defining an interior and having an upper end, a lower end, and a longitudinal axis extending through upper and lower ends; support means for supporting said conduit within said passageway with the lower end of said conduit below said surface, said conduit upper end being substantially open and defining an upwardly directed drain opening providing communication between said interior and ambient atmosphere above said surface and allowing liquid to drain from said surface directly downwardly in a vertical direction along said longitudinal axis through said drain opening into the interior of said conduit; a bottom wall connected to said peripheral wall and partially extending across said lower end to define an opening at said lower end with said peripheral wall, said bottom wall being in partial registry with said drain opening; a partition extending upwardly from said bottom wall and connected to said peripheral wall to define a trough within said conduit interior, said partition having a distal end spaced from said lower end; a deflector connected to said peripheral wall and disposed above said partition and said opening and below said drain opening whereby liquid draining from said surface directly downwardly in a vertical direction through said drain opening will directly impact said deflector, said deflector slanting downwardly and having a lower deflector edge located over said trough, said deflector having an upper liquid impact surface deflecting the liquid entering said conduit through said drain opening and directly impacting said deflector and directing said deflected liquid into said trough, said deflector also having a lower impact surface disposed over a segment of said bottom wall and over said opening; and a baffle extending downwardly from the lower deflector edge of said deflector and having a lower distal end located in said trough above said bottom wall and below the level of said partition distal end, said conduit, said bottom wall, said partition, said deflector, and said baffle being fixedly connected whereby said apparatus is of integral construction, said conduit peripheral wall, said baffle, and said partition defining a generally S-shaped fluid flow path within said interior, said generally S-shaped fluid flow path including a first fluid flow path portion disposed at a first side of said interior between said conduit peripheral wall and said baffle, a second fluid flow path portion between said baffle and said partition substantially parallel to said first fluid flow path portion and communicating therewith at said conduit lower end, and a third fluid flow path portion disposed at a second side of said interior between said conduit peripheral wall and said partition, said third fluid flow path portion substantially parallel to said first and second fluid flow path portions and in communication with said second fluid flow path portion through an aperture defined by said conduit peripheral wall, said deflector, and said partition distal end, said third fluid flow path portion leading to said opening whereby liquid in said third fluid flow path portion flowing to said opening facilitates flow of liquid through said generally s-shaped fluid flow path, said third fluid flow path portion being longer than said second fluid flow path portion whereby liquid in said third fluid flow path portion creates a siphoning effect on the liquid in said generally S-shaped fluid flow path, and said deflector lower liquid impact surface for reorienting liquid flow when said liquid flows from said second fluid flow path portion into said third fluid flow path portion.