Patent ID: 8534296

Claim:
A smoking apparatus comprising: a base chamber; a combustion bowl for containing combustible smokable material, the combustion bowl connected in an airtight manner to said base chamber; a body tube connected at a lower end in an air-tight manner to said base chamber to receive smoke from the combustion bowl, said body tube having at an upper end, opposite the lower end, an open mouthpiece from which a user draws smoke after the smoke has been filtered and cooled; a filter subassembly fitted within a lower portion of said body tube in proximity to said base chamber; a one-way valve in series with the filter subassembly, the one-way valve biased to be normally closed and to open in response to application of a negative pressure at the mouthpiece; and a diffusion subassembly comprising one or more diffusers at least partially covered with a water bath, which diffusers diffuse smoke into the water bath after application of the negative pressure has drawn the smoke through the one-way valve, wherein the one-way valve comprises a water column, wherein the water column is topologically equivalent to an inverted U-shaped tube, a first open end of the water column extends into said base chamber to receive accumulated filtered smoke, a second open end of the water column fluidically connects to deliver filtered smoke received at the first open end to an input of the diffusion subassembly during application of the negative pressure at the mouthpiece, the second open end terminating at a level that is lower than the water bath, and a region of the water column between the first open end and the second open end is entirely above an uppermost level of the water bath, and wherein upon removal of the negative pressure at the mouthpiece, a portion of the water bath covering the diffusion subassembly drains as backwash into the diffusers and is forced by atmospheric pressure into the second open end of the water column until an equilibrium is reached between a level of the water bath inside the water column and a level of the water bath outside the water column.