Air venting apparatus for WC

An air venting apparatus to be mounted into the water tank of a water closet for evacuating to the outside of the room where the water closet is located the stale air escaping from the toilet bowl, said water tank being of the type including a top edge releasably closed by a lid with a discharge pipe extending through the water inside the water tank and defining a mouth normally above water level in the tank and extending short of the level of the tank top edge;

• said apparatus comprising:
• (a) a main, generally closed, air chamber member;
• (b) a powered fan member, anchored to said air chamber member, for developing negative pressure therein;
• (c) stay means for supporting said chamber member at the top portion of said water tank spacedly above said water level;
• (d) siphon means for fluidingly interconnecting in substantially air tight fashion said discharge pipe to an upstream section of said air chamber member, whereby said siphon means is adaptable to fit discharge pipes of variable locations within said water tank wherein said siphon means includes an eccentrically shaped casing, said casing including:
• (1)an upstream mouth, adapted to remain submerged into the water of said water tank during operation of said air venting apparatus;
• (2) downstream mouth, connected to said main air chamber member for relative movement thereabout said downstream mouth located at a level above said water level;
• and
• (3) a labyrinth air passageway, extending between said upstream and downstream mouths and defining an upstream part, located above water level, a downstream part, located substantially below water level, and an intermediate section, vertically bridging said upstream and downstream parts;
• and
• (e) air outlet means, for fluidingly interconnecting a downstream end of said air chamber member to the outside of the room;
• wherein no modification of the water tank nor the water tank lid is required for the installation of said apparatus.