Abstract: A male urinal automatically flushes when the user steps off a foot plate. The foot plate pneumatically sealed is resiliently deformable and is connected by a pneumatic conduit to a normally open switch whose closure completes a circuit that opens an electrically controlled valve to flush the urinal so long as the switch is closed. Release of pressure on the foot plate creates subatmospheric pressure as the foot plate returns to its undeformed condition, which collapses a diaphragm that permits the normally open switch to close. An air bleed restores the pressure in the foot plate to atmospheric at a controlled rate that predetermines the duration of flushing.

Abstract: A pneumatically-operated bell, such as is commonly used in service stations, has twin pneumatic hoses. The first is a conventional signal hose, actuating the bell when compressed. The second hose is laid parallel to the first and, when compressed, prevents actuation of the bell by the first hose for a predetermined period. In a first embodiment, the second hose opens a switch in the bell's electric circuit. In a second embodiment, the second hose actuates a valve to block air flow through the first hose to prevent its actuating the bell. As a result, vehicles exiting the service station compress the second hose first and thus no signal is produced, while vehicles entering the station produce a signal only when the front wheels cross the hoses. Thus false signals from exiting vehicles and false double signals are prevented.