R. V. toilet venting system

In a toilet system including an upwardly opening toilet bowl having upper rim flushing water outlet means and a lower discharge outlet provided with a manually openable and closable valve, closed passage means communicating said discharge outlet with the interior of an upper portion of a holding tank disposed below said bowl and equipped with an upwardly projecting vent pipe including an upper discharge end, upper inner rim level flushing water supply means operative to supply flushing water to said flushing water outlet means and control valve means operative, responsive to manual opening of said valve, to supply water under pressure to said water supply means and to terminate the supply of water under pressure to said water supply means responsive to manual closing of said valve;

• the improvement including a remotely operable exhaust blower means operatively associated with said vent pipe for causing vapors to flow upwardly therethrough from within the upper portion of said holding tank and discharge of said vapors into the ambient atmosphere, a vent line having an inlet end and an outlet end opening into said closed passage means, a float-type liquid flow preventing valve communicating said inlet end with said flushing water supply means, said liquid flow preventing valve including fluid flow controlling means operative, in the absence of water under pressure flowing through said flushing water supply means, to allow reverse air and vapor flow through said flushing water outlet means, said flushing water supply means and into and through said liquid flow preventing valve into said vent line inlet end, and operative to prevent any flow of liquid through said liquid flow preventing valve from said flushing water supply means into said vent line inlet end in the presence of water under pressure flowing through said flushing water supply means.