Device for metering the mass of natural gas for fueling motor vehicles

Claim 1

A gas mass metering device comprising a frame supporting at least two metering chambers, a counterweight associated to each of said at least two metering chambers, a yoke member disposed in between a respective one of said at least two chambers and said counterweight for balancing and supporting each respective one of said at least two metering chambers and counterweight, at least two load measuring cells, each of said at least two load measuring cells located underneath and supporting a respective chamber of said at least two chambers, a plurality of solenoid valves adapted to control the entrance and exit of gas in said at least two metering chambers, processor means for controlling said plurality of solenoid valves, each of said at least two metering chambers defining an enclosed volume with a single opening, and at least two flexible hoses each having two ends with the first end connected to said plurality of solenoid valves and the second end connected to said single opening in a respective one of said at least two metering chambers wherein said at least two flexible hoses are provided for filling gas in said at least two metering chambers and for removing gas therefrom wherein said chambers alternatively operate with a filling step in which one of said chambers is filled with gas and a fueling step in which the other of said chambers supplies gas contained therein.