Abstract: A leak detector is connected in the main supply pipe from a gasoline storage tank to a plurality of retail gasoline pumps. A submersible motor-pump unit supplies gasoline through the pipe upon actuation of a nozzle switch at each pump. The detector, at turn-on, monitors the line pressure, and reduces flow if low line pressure indicates a system leak. Premature nozzle opening may simulate a leak and actuate the leak detector. A timed interlock switch in connected in series with the nozzle switch from the main power to related dispenser flow valves. The interlock switch includes a Triac in series with the power supply and main solenoids and a timing device including an integrated circuit having a pulsing network and a D.C. input connected in series with a rectifier to the power supply by the nozzle switch. The interlock switch has a fixed time period during which the respective flow valves are held closed such that an open nozzle does not simulate a leak.

Abstract: A mechanism for converting a two-lever gasoline dispensing pump to a single lever system. The converted single lever unit includes a frame having an upper inverted U-shaped frame section and a pair of volume and cost registers are mounted in side-by-side relation within the upper frame section. A reset mechanism is operably connected to each register and the reset mechanisms are located at opposite sides of the frame. Each reset mechanism includes a shaft and the original operating handle located on the outside of the pump is carried by a second shaft which is off-set from the reset shaft and is connected to the reset shaft through a gear drive. When the hose nozzle is removed, the operating handle can be rotated to reset or clear the register and activate the fuel valve and pump. When dispensing has been completed, rotation of the handle to its original position will deactivate the fuel valve and pump, but the register will not be cleared until a subsequent resetting cycle is accomplished.