Abstract: A portable desk for use in a vehicle having a steering wheel. An exemplary embodiment of the desk includes a generally planar working surface portion and a retainer portion adapted for engaging the steering wheel to hold the desk in a working position on the steering wheel. The exemplary embodiment of a portable desk is adapted for ready engagement with the steering wheel to support the desk in the working position and ready disengagement from the steering wheel for storage or vehicle operation.

Abstract: A waste water disposal system for recreational vehicles. When emptying the black and grey water holding tanks, grey water is emptied into the black water holding tank, thereby helping to flush solids out of the black water holding tank.

Abstract: An instantaneous, automatic gas water heater for a hot water system having a cold water supply conduit connected to a plurality of loosely wound small heat exchange tubes which, in turn are connected to a hot water outlet conduit having faucets. The heat exchange tubes are each of smaller internal diameter than the cold and hot water conduits but their total capacity is substanially the same as said conduits. A gas burner is disposed beneath the heat exchange tubes to subject them to the flame of the burner. There is a cover over the heat exchange tubes which confines the heat from the burner about the tubes. The burner is supplied with gas by a gas supply conduit controlled by a normally closed solenoid valve including a gas control valve and a solenoid controlling the gas control valve.